Dermatologic and Cosmetic Surgery Flashcards

Question

25- What is the tissue temperature is required for destruction of basal or squamous cell carcinomas with cryotherapy? A. -5° C B. -15° C C. -25° C D. -35° C E. -50° C c

Answer 1

Correct choice: E. -50° C Explanation: The temperature required for destruction of basal or squamous cell carcinoma is -50 degrees C. For melanocyte necrosis, -5 degrees C is required, and for keratinocyte treatment, -25 degrees C. c

Answer 2

Correct choice: D. 585nm Explanation: The pictured lesion is a cherry angioma, which is a vascular lesion. Thus, it should be treated by a laser with a wavelength targeting hemoglobin as a chromophore. The Pulsed dye laser set at a 585nm wavelength is the best option listed. The remaining answer choices do not target hemoglobin as a chromophore, so they would not be the best option in treating this cherry angioma: 1450nm-Diode laser (target chromophore: water) 755nm-Alexandrite laser (target chromophore: melanin) 694nm-Ruby laser (target chromophore: melanin) 510nm-short wavelength Pulsed dye laser (target chromophore: melanin)

Answer 3

Correct choice: E. Imatinib Explanation: DFSP is a malignant neoplasm that most commonly presents as a slow-growing large nodule or plaque with multiple protuberances on the trunk of middle-aged adults. It is most often due to a reciprocal translocation of t(17;22)(q22;q13) resulting in fusion of collagen 1-alpha-1 and platelet-derived growth factor B (COL1A1-PDGFB) which serves as an oncogene. This is the basis of treatment with imatinib, a PDGF inhibitor. Dabrafenib, a BRAF inhibitor, and Ipilimumab, a CTLA-4 inhibitor, are used in the treatment of metastatic melanoma. Gefitinib and Erlotinib are EGFR inhibitors that do not have efficacy in the treatment of DFSP.

Answer 4

Correct choice: B. Kidney transplant patients are at the highest risk of developing cutaneous malignancies Explanation: Heart transplant patients are at the highest risk of cutaneous malignancies due to the extent of immunosuppresion they get.All the other answer choices represent true statements.

Answer 5

Correct choice: A. Polydioxanone Explanation: Polydioxanone (PDS) is a polymer of paradioxanone. It is a monofilament, absorbable suture with 180 d absorption and low reactivity. The tensile strength is the greatest, and it lasts the longest. The tensile strenght of PDS is 50% at 30 days. Polypropylene is not an absorbable suture and the other listed absorbale sutures do not have as a high a tensile strength as PDS. The tensile strenght of polyglactin is 50% at 21 days. The tensile strenght of polyglycolic acid is 20% at 21 days. The tensile strenght of Poliglecaprone 25 is 50% at 7 days.

Answer 6

Correct choice: C. 1.0cm Explanation: The recommendation for a margin excision for in situ melanomas is 0.5cm (not including lentigo maligna forms). Margin excision for a melanoma up to 1mm in thickness is 1.0cm. Thickness between 1.01-2mm requires a 1-2cm surgical margin, and >2cm is needed when the tumor thickness reaches 2mm. The recommendation for a margin excision for in situ melanomas is 0.5cm (not including lentigo maligna forms). Margin excision for a melanoma up to 1mm in thickness is 1.0cm. Thickness between 1.01-2mm requires a 1-2cm surgical margin, and >2cm is needed when the tumor thickness reaches 2mm.

Answer 7

Correct choice: C. Angular artery Explanation: Angular artery provides blood supply for the nasolabial transposition flap. c

Answer 8

Correct choice: C. The parallel nature of a beam of light Explanation: Collimation refers to the parallel nature of light beams that make a laser focused on even small spot sizes. Monochromicity refers to a single wavelength, coherence refers to light traveling in phase. Light that is amplified traveling back and forth between the laser’s mirrors is how lasers operate. Perpendicular beams of light that increase scatter are not related to collimation.

Answer 9

Correct choice: C. Sodium morrhuate Explanation: The highest risk of anaphylaxis is with sodium morrhuate (Choice 3). Other side effects include pain, skin necrosis, and hyperpigmentation. Glycerin (Choice 1) and hypertonic saline (Choice 4) alone do not carry any risk of anaphylaxis. There is a very rare risk of anaphylaxis with polidocanol (Choice 2) and sodium tetradecyl sulfate (Choice 5).

Answer 10

Correct choice: C. Nd:YAG 1064 nm Explanation: Nd:YAG 1064nm. The ranges provided by the laser glasses indicate the wavelenghts the glasses protect for. It is important to note a crystal, such as Nd:YAG may produce more than one wavelenght. Reference: Reference: Robinson. Surgery of the Skin. 2nd Ed. Chapter 33.

Answer 11

Correct choice: D. Inadequate undermining Explanation: The arrow is pointing to an area of a trapdoor deformity which presents as pincushioning or a protuberant appearance of a flap. Commonly it presents 3-6 weeks post-op and is very common on the nose. It is likely due to circumferential contraction of the flap causing the flap to buckle. Ways to reduce this outcome is to undermine extensively under the entire flap and surrounding edges, properly size a flap (no oversize it or "stuff" it), square the edges of the flap as U-shaped flaps are more likely to buckle, and thin the flap appropriately. Oversizing the flap rather than undersizing can lead to trapdoor/pin-cushioning. Hematoma, post-op infection and flap necrosis can all lead to poor outcomes of healing but not as likely to cause trapdoor deformity.

Answer 12

Correct choice: D. 75% Explanation: A Z-plasty is a transposition flap used to treat wound contractures and scars. It is performed to decrease tension on a wound, change the orientation of a scar, and improve overall scar appearance. A 60-degree Z-plasty will yield a 75% increase in scar length and a 90-degree change in scar direction. A 45-degree Z-plasty will yield a 50% increase in scar length, and a 30- degree Z-plasty will yield a 25% increase in scar length.

Answer 13

Correct choice: A. Mohs micrographic surgery with repair Explanation: Mohs micrographic surgery is the correct choice for the patient presented who has a 6 mm basal cell carcinoma located on the nasolabial fold in the region of the apical triangle. While the patient may elect not to proceed with therapy or choose a therapy with a lower cure rate compared to Mohs micrographic surgery, the most appropriate treatment option should be encouraged. Excision would offer the second highest cure rate for a 6 mm basal cell carcinoma at the apical triangle of the face, but is sub-optimal to Mohs micrographic surgery. Radiation should not be used for this basal cell carcinoma that can otherwise be surgically approached. Electrodessication and curettage and cryotherapy and curettage do not offer appropriate cure rates for a basal cell carcinoma on the face of our patient.

Answer 14

Correct choice: B. Plain gut Explanation: Plain gut has the highest tissue reactivity amongst absorbable sutures. Chromic gut has high tissue reactivity, but it is less so than plain gut. The other answer choices have low tissue reactivity.

Answer 15

Correct choice: A. Angular artery Explanation: The identified structure is the angular artery. After forming the superior labial branch, the facial artery becomes known as the angular artery.The pictured structure is wider caliber vessel, thus not a nerve. The superior labial artery and the transverse facial artery have lateral-medial orientations as opposed to the caudal-cephalad orientation of the angular artery/facial artery.

Answer 16

Correct choice: E. 10,600 nm Explanation: CO2 resurfacing and ablative lasers (10,600 nm) are the best for severe rhinophyma as is seen here. The other wavelengths represent lasers that will be less effective in treating the disease at this late stage.

Answer 17

Correct choice: B. Proteolysis Explanation: Fast absorbing gut is made up of a natural fiber. Natural fibers include those that are absorblable such as surgical gut, and those that are nonabsorbable such as silk. Absorbable natural sutures are broken down by proteolysis. Synthetic absorbable sutures are broken down by hydrolysis.

Answer 18

Correct choice: B. Imbibition, inosculation, neovascularization, maturation Explanation: All successful grafts go through the following stages: 1. Imbibition – for the first 48 hours the graft is sustained by plasma from the recipient bed, hyperemia 1-3 days 2. Inosculation – on day 2-3 blood vessels in the graft establish connections with the wound bed 3. Neovascularization – ingrowth of new vessels into the graft occurs at approximately one week 4. Maturation – months post-grafting, sensory innervation occurs and the graft becomes paler Reference: Reference: Dermatology In-Review. 2016-2017 ed. p512.

Answer 19

Correct choice: A. Iris scissor Explanation: Iris scissor. They have two sharp points and used for tissue dissection. Reference: Reference: Robinson. Surgery of the Skin. 2nd ed. Ch. 4

Answer 20

Correct choice: A. Great auricular nerve Explanation: The great auricular nerve(C2, C3) exits approximately 6.5 cm below the external auditory canal along the posterior border of the sternocleidomastoid muscle and extends superiorly. Injury leads to numbness of the inferior two-thirds of the ear and the adjacent cheek and neck.

Answer 21

Correct choice: B. Full-thickness skin graft Explanation: This is an example of a full thickness skin graft. There is a circular graft on the ear, and a linear scar on the preauricular cheek indicating this as the donor site. Donor sites are commonly taken from the pre or post-auricular skin as it is easy to hide the scar in those locations. A split thickness graft is composed of epidermis and some dermis and is very thin. The donor site is usually left to heal by secondary intent and taken from a site that is easy to conceal, therefore there would not be a linear scar on the preauricular cheek. A composite graft typically includes 2 tissue types such as cartilage and skin. Although composite grafts can be use to repair ears to rebuild the structure/foundation, it would require cartilage to be taken from a donor site on the nose or ear, and the photo does not show any donor sites that would indicate this. In addition a very small defect, such as the one shown in this image, would likely not require cartilage. An interpolation or transposition flap would not have a linear scar at the preauricular cheek.

Answer 22

Correct choice: C. 40% Explanation: A scar's strength at 6 weeks is 40%. Scar strengths based on timeframe: 2 weeks- 5% 3 weeks- 15% 6 weeks- 40% 6 months- 70% 1 year- 80% (maximum strength of scar compared to original strength prior to injury/surgery)

Answer 23

Correct choice: B. Purple Explanation: Pigmentation defects or discolorations can be camouflaged either by applying an opaque cosmetic that allows none of the abnormal underlying skin tones to be appreciated or by applying foundations of complementary colors. For example, red discoloration can be camouflaged by applying a green foundation, since green is the complementary color to red. The blending of the red skin with the green foundation yields a brown tone, which can be readily covered by a more conventional facial foundation. Furthermore, yellow skin tones can be blended with a complementary-colored purple foundation to also yield brown tones. 1 - Green: Red discoloration can be camouflaged by applying a green foundation, since green is the complementary color to red. 3 - Brown: Brown hyperpigmentation from skin conditions such as melasma, lentigines, and nevi can be camouflaged by using a white undercover foundation color. 4 - White: Hypopigmentation and depigmentation from skin conditions such as postinflammatory hypopigmentation, congenital pigmentary disorders and vitiligo can be cmouflaged by using a brown undercover foundation color. 5 - Yellow: Yellow facial color from conditions such as solar elastosis, chemotherapy and dialysis can be camouflaged by applying a purple undercover foundation color.

Answer 24

Correct choice: A. Imbibition Explanation: Imbibition is the first stage of healing for skin grafts. It takes place during the first 48 hours where the graft is recieving nutrients by passive diffusion from the underlying wound bed. It is imperative that there is good connection/adherence of the flap with the wound bed for this to occur. This can be acheived with basting (tacking or quilting) sutures and a bolster. The bolster also provides stability and protection from trauma to the delicate graft. Inosculation occurs after 2-3 days later, where the blood vessels in the graft start to establish connections to the underlying wound bed. Neovascularization is the growth of new vessels into the graft between 4-7 days. Maturation or Reinvervation occurs months after the graft is placed where sensory innervation develops and the graft becomes paler. Delayed phase is not a known healing phase for grafts.

Answer 25

Correct choice: E. Inactivated by blood Explanation: Iodophor (Betadine) is an antiseptic in the halogen class with moderate onset of activity that is sustained up to 1 hour. Spectrum includes gram+ and gram- organisms. It is absorbed through skin, must be dry to be effective, is tissue damaging, and inactivated by blood. It sometimes causes an allergic contact dermatitis.

Answer 26

Correct choice: E. Electrofulguration Explanation: The correct answer is electrofulguration (Choice 5), in which there is superficial ablation where the tip of probe does not contact the skin. This method allows an electric spark to jump to the skin causing superficial epidermal carbonization, protecting the underlying tissue from heat. Choice 1 is incorrect as electrocautery is not true electrosurgery because there is no current running through the patient. Instead, electrocautery uses heat to achieve hemostasis. Electrocoagulation (Choice 2), electrodessication (Choice 3), electrosection (choice 4) involve the probe being in direct contact with the tissue.

Answer 27

Correct choice: D. Muscle spasms Explanation: Vismodegib is smoothened (SMO) inhibitor approved for the treatment of adults with basal cell nevus syndrome, metastatic or locally advanced BCC that has recurred following surgery or who are not candidates for surgery or radiation. The most commonly reported side effect is muscle spasm, followed by alopecia and dysgeusia.

Answer 28

Correct choice: E. A, B, & C Explanation: Secondary intention healing occurs when the wound is allowed to heal on its own. This process allows for healing primarily by the contraction of myofibroblasts. It may be an excellent alternative for select defects, ie. surgical defects on concave areas, such as the medial canthus, alar crease, temple (as long as the defect is not too close to a free margin or anatomical landmark), and conchal bowl (as long as defect does not approach the external auditory meatus). The remaining answer choices are incorrect.

Answer 29

Correct choice: B. Hydrogels Explanation: Hydrogels are good for dry painful wounds. Foams are absorptive. Hydrofilms are occlusive, allowing gas and water vapor to permeate. Hydrocolloids are fibrinolytic, cause angiogenesis, inhibit keratinocyte migration, antibacterial increases healing rate, can cause surrounding maceration. Alginates are the most absorptive and are turned into gel by the wound exudate.

Answer 30

Correct choice: E. Vitamin K Explanation: Vitamin K oxide gel appears to hasten the resolution of pulsed dye laser- induced purpura in subjects being treated for bilateral facial telangiectasia, and may well be useful in accelerating resolution of facial bruising from other cosmetic procedures such as fillers used for soft-tissue augmentation as well as other types of cutaneous surgical procedures.

Answer 31

Correct choice: D. Cathelicidin Explanation: Cathelicidin is an anti-microbial peptide in human epidermis thought to be upregulated in conditions such as psoriasis and rosacea. The remainder of the answers are all antioxidants which are naturally found in the skin. Research into the preventive role of topical antioxidants in photoaging is based on the free radical theory of aging. Epidermal depletion of these substances has been shown to be an early and sensitive marker of environmental oxidative damage.

Answer 32

Correct choice: B. tumescent anesthesia Explanation: Tumescent anesthesia is used for endovenous radiofrequency ablation and endovenous laser ablation. This allows separation of the vessel from the surrounding tissue, thereby protecting surrounding tissue (including nerves) from injury. Endovenous ablation procedures can be done in an outpatient setting, without general anesthesia. 1% sodium tetradecyl sulfate is a sclerosant, not an anesthetic.

Answer 33

Correct choice: A. Half-buried horizontal mattress suture Explanation: A tip stitch is a half-buried horizontal mattress suture. It is most commonly used to align tissue and secure the tips of flaps. A pulley suture is a modified vertical mattress suture and is used for areas of high tension. The other options are incorrect.

Answer 34

Correct choice: A. Polydioxanone Explanation: Polydioxanone (PDS) is an absorbable suture that lasts 180 days and is good for high tension areas such as the leg. Monofilament sutures such as poliglecaprone 25 and glycomer 631 work, but not as well in terms of duration of tensile strength for high tension areas.

Answer 35

Correct choice: A. Imbibition Explanation: A full thickness skin graft was used here to repair the post-surgical defect. A full thickness skin graft consists of the entire epidermis and dermis, the subcutaneous tissue removed prior to inset to avoid graft compromise. All successful grafts go through the following stages: imbibition (first 48 hours), inosculation (day 2-3), neovascularization (~1 week), and maturation (months post-grafting).

Answer 36

Correct choice: C. Conchal bowl Explanation: A ring block around the ear anesthetizes the entire ear, except for the conchal bowl and external auditory meatus. The vagus nerve provides the cutaneous sensation for the conchal bowl. The great auricular nerve innervates the majority of the posterior ear, as well as 3/4 of the anterior helix. The auriculotemporal nerve innervates the tragus, anterior helix and part of the superior helix.

Answer 37

Correct choice: C. CN XI Explanation: Injury of the spinal accessory nerve results in the inability to elevate the shoulder on the affected side, winged scapula, and the inability to initiate arm abduction.

Answer 38

Correct choice: A. A logarithmic measure of the power transmission factor Explanation: The O.D. stands for optical density, identifying the amount of the medium that may penetrate a protection filter. This is a logarithmic measure: for example, O.D. of 4 means that the optical power is attenuated by the factor 10 to the power of 4= 10000 times. E is the definition of coherence. Reference: https://safety.vanderbilt.edu/laser/glossary-laser-terms.php https://www.rp- photonics.com/optical_density.html

Answer 39

Correct choice: C. Moderate to severe obesity are contraindications to liposuction Explanation: Liposuction is not intended for weight reduction. Moderate obesity is relative contraindication, while severe obesity is an absolute contraindication. The upper limit of fat extraction in one setting is 4500-5000mL, according to American Academy of Dermatology guidelines. Beyond this, fluid shifts can occur, resulting in cardiovascular compromise. Liposuction does not improve the appearance of cellulite. Tumescent anesthesia in the office for liposuction has a high safety profile. The serious complications seen in liposuction are associated with general anesthesia, not with procedures performed with local tumescent anesthesia. Although deaths have been reported during liposuction, none has occurred when patients were treated with tumescent anesthesia alone. Office-based tumescent liposuction performed by dermatologic surgeons is safe and has a lower complication rate than hospital-based procedures.

Answer 40

Correct choice: D. Excision with 10 mm margin Explanation: The correct approach is excision with 10 mm (1 cm) margin with repair. 5 mm and 15 mm are not the appropriate margins for excision of a 0.35 mm BD melanoma and sentinel lymph node biopsy is not indicated. Radiation therapy is not the appropriate treatment.

Answer 41

Correct choice: E. With regard to biopsy site identification prior to surgery, photographic documentation does not improve accuracy compared to clinical notes and diagrams Explanation: The correct answer is E (E is false). Photographic documentation has shown to improve biopsy site identification prior to Mohs surgery [ii. Hansen TJ, Lolis M, Goldberg DJ, MacFarlane DF. Patient safety in dermatologic surgery: Part I. Safety related to surgical procedures. J Am Acad Dermatol. 2015 Jul;73(1):1-12. ]

Answer 42

Correct choice: D. Between the lateral eyebrow and anterior hairline Explanation: The temporal nerve runs 0.5cm below the tragus to 1.5cm above the lateral brow. The danger zone of the temporal branch of CN VII occurs within a 2 cm box from lateral eyebrow to anterior hairline where it runs beneath the SMAS. Injury to this nerve results in unilateral forehead paralysis, ipsilateral forehead flattening, and eyelid ptosis.

Answer 43

Correct choice: D. arms Explanation: Compartment syndrome can occur in the arms, distal to the area infused with tumescent anesthesia due to fluid compression. Avoid anterior flexural surfaces. Postliposuction edema can occur in the thighs and abdomen. For example, circumferential liposuction of the thigh can theoretically cause prolonged postoperative edema by precipitating a vicious cycle and temporarily obliterating a significant portion of lymphatic drainage from the lower limb. This liposuction-induced edema produces a mild compartment syndrome with local hematic capillary ischemia, decreasing delivery of oxygenated blood, augmenting anaerobic metabolism, and increasing capillary permeability. This increased capillary permeability produces still more edema.

Answer 44

Correct choice: E. Plain gut Explanation: Of the absorbable sutures listed, plain gut absorbs most rapidly (absorption complete in 60-70 days). Chromic gut completely absorbs in ~80 days. Polyglactin 910 (Vicryl) and polyglycolic acid (Dexon) are both absorbed in about 90 days. Polydioxanone (PDS) is an absorbable monofilament which takes approximately 180 days to completely absorb.

Answer 45

Correct choice: A. Mercuric sulfide Explanation: Allergic reactions have been reported with several different types of tattoo pigment. The most commonly associated tattoo pigment, however, is mercuric sulfide. Tattoos with mercuric sulfide appear red in color. Titanium dioxide (white tattoo color), Cadmium sulfide (yellow tattoo color), Ferric oxide (brown tattoo color), and Iron oxide (black tattoo color) are less commonly associated with allergic reactions. Of note, Cadmium sulfide is the tattoo pigment most commonly associated with phototoxic reactions.

Answer 46

Correct choice: C. Treat with a high-potency topical steroid Explanation: Allergic contact dermatitis to triple-antibiotic ointment or tape is a common complication or pitfall after surgery. The initial appropriate steps are to withdraw the likely source of allergen and treat with high-potency topical steroids. In the future, patch testing may be an appropriate investigation to pursue. Administration of non-steroidal anti-inflammatories is not necessary and is not the best single answer choice.

Answer 47

Correct choice: D. KIT Explanation: Mucosal melanomas tend to have an activating mutation in KIT. GNAQ mutations are seen in both uveal melanomas and blue nevi. Cyclin dependant kinase 4/6 binds cyclin D and together phosphorylate Retinoblastoma. MDM2 targets p53 for ubiquitination.

Answer 48

Correct choice: D. Inferior labial artery Explanation: The photograph demonstrates a wedge resection which is used to repair defects of the lower lip. During this repair, the inferior labial artery is likely to be severed since it courses superficially between the mucosa and the underlying muscle. The angular artery, mental nerve, buccal nerve, and marginal mandibular nerve are unlikely to be severed during a wedge resection of the lower lip.

Answer 49

Correct choice: B. If the patient develops post-inflammatory hyperpigmentation, then hydroquinone is effective in treatment Explanation: Hydroquinone does reduce post-inflammatory hyperpigmentation if it does develop after laser resurfacing. The 1999 paper by West and Alster demonstrated that pretreatment with hydroquinone did not reduce the risk of hyperpigmentation after CO2 laser resurfacing. Antivirals have been shown, when prophylactically given, to reduce HSV outbreaks before medium depth peels and resurfacing in those prone to outbreaks. Isotertinoin should be completed 6-12 months prior due to atrophy of pilosebaceous units, thus increasing scarring risk after ablative CO2 laser resurfacing.

Answer 50

Correct choice: D. Mohs surgery Explanation: Mohs surgery. Mohs surgery is the treatment of choice for DFSP. The local recurrence rate is 1% with Mohs surgery (vs. 15-50% with wide local excision). Imatinib is approved for unresectable or metastatic disease and targets the COL1A1-PDGFB fusion protein.

Answer 51

Correct choice: E. Inability to depress and retract the lip on the affected side Explanation: The marginal mandibular nerve innervates the depressor anguli oris, depressor labii inferioris, mentalis, orbicularis oris, risorius, and platysma muscles. Depression and retraction of the lip is controlled by depressor anguli oris, depressor labii inferioris, and mentalis muscles. An injury to the marginal mandibular nerve would thus cause an inability to smile, and interfere with depression and retraction of the lip on the affected side. The mouth would seem normal at rest, but crooked when attempting to smile. 1 – A marginal mandibular nerve injury does not present with difficulty swallowing. 2 – A marginal mandibular nerve injury does not present with frequent salivation on the injured side. 3 – The buccal nerve innervates the buccinators which help to prevent accumulation of food between teeth and buccal mucosa with chewing. 4 – The buccal nerve innervates the zygomaticus minor, levator labii superioris, and risorius which elevate and retract the lip.

Answer 52

Correct choice: A. Submucosal Explanation: The inferior labial artery is derived from the facial artery or superior labial artery, and runs through the submucosal tissue horizontally. The inferior labial artery does not typically lie in the other listed anatomic planes.

Answer 53

Correct choice: A. Chlorhexidine rinses (0.12%) aid in prevention of drug-associated gingival enlargment Explanation: Chlorhexidine rinses help prevent drug-associated gingival enlargement. Chlorhexidine is irritating to eyes and middle ear. It has no effect on suture strength. ChloraPrep is a combination of chlorhexidine and isopropyl alcohol. Reference: Reference: Dermatology. Bolognia, Jorizzo, Schaffer. 3rd ed. Ch 72.

Answer 54

Correct choice: C. Medical therapy is used in conjunction with hair transplant to maximize hair density Explanation: Medical therapy such as minoxidil and finasteride are often used in conjunction with hair transplantation to maximize density and minimize ongoing hair loss. Patients should be counseled that androgenetic alopecia (AGA) is an ongoing process. The progressive nature of AGA means that additional hair transplants may be required in 5-10 years. The physician should emphasize before the procedure how ongoing hair loss will affect the density and cosmetic appearance of the transplant. If medications are discontinued, the patient can expect loss of hairs grown or maintained by their use.

Answer 55

Correct choice: E. interleukin (IL)-4 Explanation: Imiquimod is a topical immunomodulator that is FDA-approved for the treatment of genital warts, actinic keratosis and superficial basal cell carcinomas. It induces toll like receptor (TLR) 7 and the production of Th-1 cytokines including tumor necrosis factor (TNF)-α , interferon (IFN)-γ , interferon (IFN)-α , and interleukin (IL)-12, leading to stimulation of a cell-mediated immune response. IL-4, IL-5, IL-6 and IL-13 are Th-2 cytokines.

Answer 56

Correct choice: A. Bishop-Harmon forceps Explanation: Bishop-Harmon forceps Reference: Reference: Dermatology. Bolognia, Jorizzo, Schaffer. 3rd ed. Ch 144.

Answer 57

Correct choice: C. Mandibular nerve Explanation: This patient has Frey syndrome or auriculotemporal nerve syndrome. This is characterized by facial flushing, sweating, or both localized to the distribution of the auriculotemporal nerve (a branch of the mandibular nerve) that occurs in response to gustatory stimuli. In adults, the syndrome usually results from surgical injury or trauma to the parotid gland.

Answer 58

Correct choice: E. No antibiotics Explanation: This patient does not require preoperative antibiotics. The presence of implantable defibrillators and pacemakers are not indications for antibiotic use. Patients with mitral valve prolapse without valvular insufficiency or regurgitation noted on ultrasound are at no higher risk for bacterial endocarditis than the general population and, therefore, do not require preoperative antibiotics. According to the AHA, those patients who are at high risk for bacterial endocarditis and require preoperative antibiotics include those with prosthetic cardiac valves, previous bacterial endocarditis, complex cyanotic congenital heart disease, and surgically constructed systemic-pulmonary shunts. Moderate risk patients include those with mitral valve prolapse with regurgitation, acquired valvular dysfunction, and hypertrophic cardiomyopathy

Answer 59

Correct choice: D. Polypropylene (Prolene) Explanation: Prolene is a nonabsorbable suture material that evokes only minimal inflammation. Vicryl, Dexon, silk and surgical gut are associated with more inflammation than prolene.

Answer 60

Correct choice: D. Transposition flap Explanation: A Z-plasty is a type of transposition flap that is useful for scars crossing relaxed tensions lines or releasing contractures (redistributes tension over wound). A Z-plasty involves the movement of tissue via transpositioning across intervening islands of unaffected tissue. Therefore, the remaining answer choices are not correct.

Answer 61

Correct choice: E. Previous bacterial endocarditis Explanation: Preoperative antibiotics are recommended for endocarditits prophylaxis in select high risk patients that undergo high risk procedures. High risk procedures are procedures that involve manipulation of gingival tissue or the periapical region of teeth or perforation of the oral mucosa. High risk patients are, according to the guidelines, those with the following: Prior infective endocarditis, Prosthetic cardiac valves, Unrepaired cyanotic congenital heart defects, including palliative shunts and conduits, congenital heart defects completely repaired with prosthetic material or a device, whether placed by surgery or by catheter intervention, during the first 6 months after the procedure, repaired congenital defects with residual defects at the site or adjacent to the site of a prosthetic patch or prosthetic device, cardiac transplants and development of cardiac valvulopathy. Patient groups that may have received routine antibiotic prophylaxis in the past but are no longer candidates for it include those with mitral and aortic valve disease, rheumatic heart disease, or structural disorders like ventricular or atrial septal defects or hypertrophic cardiomyopathy, according to the AHA statement. The revised guidelines were developed with the participation of and have been endorsed by the American Dental Association, the Infectious Diseases Society of America, and the American Academy of Pediatrics. Classically 1 gram of Dicloxacillin or cephalexin is given 1 hour preoperatively and an additional 500 mg is given 6 hours post op. Clindamycin can be givenin those patients who are penicillin allergic. Patient groups that may have received routine antibiotic prophylaxis in the past but are no longer candidates for it include those with mitral and aortic valve disease, rheumatic heart disease, or structural disorders like ventricular or atrial septal defects or hypertrophic cardiomyopathy, according to the AHA statement.

Answer 62

correct choice: A. 3 weeks Explanation: This is an interpolation flap and the optimal time for take down is 3 weeks after the flap is done.

Answer 63

correct choice: B. Gradle scissors Explanation: The pictured instrument is a gradle scissors. The tip has a curvature which approximates a cradle, which rhymes with gradle.

Answer 64

Correct choice: B. Motorized dermabrasion Explanation: Moderate to severe acne scarring is the most notable condition for which motorized dermabrasion is the preferred resurfacing modality. Laser resurfacing has yielded variable results and chemical peeling is generally disappointing. Dermabrasion selectively planes the affected skin. Carbon dioxide laser ablation and trichloroacetic acid chemical peels may efface the edges of atrophic scars but are more difficult with less predictable results compared to dermabrasion. Conventional motorized dermabrasion remains the gold standard in resurfacing procedures for atrophic or boxcar acne scars. 1 – Pulsed dye laser is not an effective resurfacing treatment option for moderate to severe acne scarring. 3 – Intense pulsed light is not an effective resurfacing treatment option for moderate to severe acne scarring. 4 – Effacing the edges of atrophic scars can be accomplished with the carbon dioxide laser but may be more difficult and with less predictable results compared to dermabrasion. 5 – Chemical peels are generally disappointing for moderate to severe acne scarring. Effacing the edges of atrophic scars can be accomplished with a 35% trichloroacetic acid peel but is more difficult and has less predictable results compared with dermabrasion.

Answer 65

Correct choice: A. Angular artery Explanation: The angular artery courses up the nasolabial fold and is deep to the nasal alar groove and is often encountered with this V to Y repair. The other arteries are not located in this area. The anterior ethmoidal nerve supplies sensation to the columella and nasal tip.

Answer 66

Correct choice: B. 308 nm Explanation: The operational wavelength of the 308 nm excimer laser and lamp is close to that of NB-UVB. The therapeutic benefit of the excimer laser for vitiligo has been investigated in multiple studies, and, overall, 20–50% of lesions achieve ≥75% repigmentation; the excimer lamp appears to have similar efficacy. Localized patches of vitiligo are treated one to three times weekly for an average of 24 to 48 sessions, with the repigmentation rate depending on the total number of sessions, not their frequency. Erythema and (rarely) blistering represent potential side effects.

Answer 67

Correct choice: B. Hyaluronic acid Explanation: Hyaluronic acid. Poly-L-lactic acid (Sculptra), polymethyl methacrylate (Artefill/ Artecoll), silicone and calcium hydroxyapatite (Radiesse) are all much more likely to cause nodules in the perioral area than hyaluronic acid fillers.

Answer 68

Correct choice: C. To avoid important anatomic structures Explanation: This is a diagram of a M-plasty, which is used to shorten the length of a scar in order to avoid important anatomic structures. The other choices are untrue.

Answer 69

Correct choice: D. Not enough undermining Explanation: This is a photograph of trap door deformity which occurs when not enough undermining is performed.

Answer 70

Correct choice: A. Pulsed dye laser Explanation: The pulsed dye laser (PDL) is considered to be the laser of choice for the treatment of many cutaneous vascular lesions, especially facial telangiectasias, port-wine stains, superficial hemangiomas, poikiloderma of Civatte, and erythematotelangiectatic rosacea. B - KTP laser: KTP laser can be used to effectively treat some vascular lesions (e.g. telangiectasias) in a purpura-free manner. While it can be used to treat vascualr lesions including telangiectasias, pulsed dye laser is the laser of choice for treatment of cutaneous vascular lesions such as telangiectasias. C - Intense pulsed light: IPL is most commonly used for patients with phototypes IIII with chronic photodamage or for hair removal. For treatment of patients with more darkly pigmented skin, longer wavelength filters or lower fluences plus longer pulse widths can be used. Filters can also be used for other specific indications, e.g. treatment of vascular lesions. Although it can be used to treat vascular lesions, PDL is considered to be the laser of choice for treatment of facial telangiectasias. D - Diode laser: Diode lasers can be used to treat leg venulectasias and telangiectasias ("spider veins"), blue reticualr veins, and venous malformations. However, a pulsed dye laser is considered to be the laser of choice for treatment of facial telangiectasias. E - Nd:YAG laser: The deeply penetrating Nd:YAG 1064 nm laser has significantly less hemoglobin absorption than the wavelengths of the PDL or KTP lasers. This laser can be used to treat deeper vascular lesions and spider veins up to 3 mm in size. Because of its poor coefficient of absorption by hemoglobin, much higher fluences are required to produce transmural heating of blood vessels. Nd:YAG lasers should be used with extra caution when treating vascular lesions.

Answer 71

Correct choice: C. 532nm Explanation: These are telangiectasias which are most effectively treated with the long pulsed 532nm KTP laser. The 1550nm, the CO2 10600nm and the erbium 2940nm lasers target water and do not target the hemoglobin. The alexandrite 755nm targets melanin not hemoglobin

Answer 72

Correct choice: E. Gradle scissors Explanation: Gradle scissors have delicate sharp tips, making them ideal for skin tag removal. Obrien scissors and Spencer scissors are suture scissors. Obrien scissors have angled tips, whereas Spencer have a characteristic round suture hook. Baby and large Metzenbaum scissors have blunt tips and are used for undermining tissue.

Answer 73

Correct choice: C. Subcutaneous fat Explanation: To avoid injury to the temporal branch of the facial nerve in this area, undermining should occur in the subcutaneous fat layer. Undermining deeper than the subcutaneous fat layer (SMAS or muscle) could risk injury to the temporal branch of the facial nerve.

Answer 74

Correct choice: C. Serial normal saline injections to the area Explanation: Saline injections in serial fashion are the least invasive, least costly option to offer the patient. Injections are performed every 1-2 weeks for at least 2 months before evaluating for success or failure. The remaining choices are incorrect as the first, least invasive option.

Answer 75

Correct choice: C. Povidone-iodine Explanation: The image shows a pathologic photo of sebaceous carcinoma. The most common location of sebaceous carcinoma is the upper eyelid. Given this location, povidone-iodine is the best answer. Of note, it must be allowed to completely dry before starting surgery. Chlorohexidine's exposure to the eyes can cause keratitis and therefore should be avoided in these areas. Isopropyl alcohol has not demonstrated toxic effects on the eyes and can be used safely, but is typically too short acting for surgery. Hexachlorophene causes neurotoxicity and is teratogenic so is rarely used today. Normal Saline has not demonstrated toxic effects on the eyes and can be used safely, but does not have antiseptic properties.

Answer 76

Correct choice: D. Bovine collagen Explanation: Bovine collagen is contraindicated in the glabella due to necrosis, however, extreme caution must be used when injecting any filler in the glabellar region as it is a watershed area. Injection necrosis is a rare but clinically important potential complication caused by interruption of the vascular supply to the area by compression, injury, and/or obstruction of the vessel(s). The glabella is a particular danger zone for injection necrosis regardless of the type of filler used, however bovine collagen poses a greater risk of developing this side effect.

Answer 77

Correct choice: B. 12032 with 58 modifier Explanation: This question describes a malignant excision, which has a 10 day global period. Therefore, the repair that was performed on day 5 in this scenario falls into this global period. Given this, the repair code 12032 will require a modifier. The correct answer is the 58 modifier, which describes a related/staged procedure by the same physician within a global period. The 25 modifier designates a separate E/M on the same day as a procedure. The 59 modifier is a clinically distinct procedure performed on the same day by the same physician. The 79 modifier designates an unrelated procedure by the same physician in a global period.

Answer 78

Correct choice: D. 30 Explanation: This is an ellipse, and the optimal angle between the apices is 30 degrees. In rhombic transposition flaps, the rhombus consists of two 60-degree angles and two 120-degree angles.

Answer 79

Correct choice: C. 99213 with 24 modifier Explanation: Adjacent tissue transfer/Flap reconstruction after Mohs surgery has a 90 global period. This visit is an unrelated E/M during a global period, and would therefore require a modifier 24. Modifier 25 designates a procedure on the same day/visit as an E/M. Modifier 59 designates 2 separate and distinct procedures were performed on the same day. Modifier 79 is a separate procedure performed by the same physician during a global period.

Answer 80

Correct choice: C. Immunosuppression with mTor inhibitor Explanation: All organ transplant recipients are at increased risk for the development of cutaneous malignancies. However, the above-mentioned factors, with the exception of choice E, place these individuals at further risk. Sirolimus (mammalian target of rapamycin inhibitor) has shown evidence of decreasing the risk of post-transplantation skin cancer incidence. Post-transplant skin cancer is common, with elevated risk imparted by increased age, white race, male sex, and thoracic organ transplantation.

Answer 81

Correct choice: E. CO2 laser resurfacing for facial wrinkles Explanation: This stem describes a woman with a corneal ulceration. This typically presents with burning pain at the site of exposure followed by tearing and blurred vision. CO2 lasers have wavelengths of 10,600 nm which targets the chromophore of water. Lasers > 800 nm can damage the cornea, which is a water containing structure. Therefore, exposure of CO2 to the eye can cause corneal injuries. Nd:YAG (1320 nm), diode (1440 nm), Er:glass (1550 nm), Er:YAG (2940 nm) can also cause corneal damage. Lasers < 800 nm damage the retina, iris, uvea, and choroid (pigment-containing structures). PDL has target wavelength of 585-595 nm Q-Alex has target wavelength of 755 nm KTP has target wavelength of 532 nm These wavelengths are therefore too short to damage the cornea.

Answer 82

Correct choice: B. Anterior ethmoidal Explanation: The external nasal nerve innervates the columella and nasal tip. It is a branch of the anterior ethmoidal nerve, which provides branches of V1. The infratrochlear is also a branch of V1 but it supplies the nasal root and medial canthus. The infraorbital and zygomaticotemporal are branches of V2. The buccal is a branch of V3. Most of the sensory innervation of the nasal cavity is derived from two sources: the sphenopalatine ganglion and the anterior ethmoidal nerve. The sphenopalatine ganglion (pterygopalatine, nasal, or Meckel's ganglion) is a parasympathetic ganglion that is located in the pterygopalatine fossa, posterior to the middle turbinate. Its sensory root is derived from sphenopalatine branches of the maxillary nerve, cranial nerve (CN) V2. As they pass through the sphenopalatine ganglion, these sensory branches form the greater and lesser palatine nerves, which provide sensory innervation to the nasal cavity as well as the roof of the mouth, soft palate, and tonsils. The anterior ethmoidal nerve is one of the sensory branches of the ciliary ganglion, which is located within the orbital cavity and inaccessible to nerve blocks. It provides sensory innervation to the anterior portion of the nasal cavity.

Answer 83

►B Breast enlargement is a relatively common and unexpected side effect of tumescent liposuction. Since the majority of these patients report increased breast size in the absence of weight gain, some authors postulate shifting hormone ratios as the etiology of this paradoxical breast augmentation.Abdominal perforation, respiratory failure and pulmonary embolus are complications that are seen almost exclusively in liposuction patients that receive general anesthesia or intravenous sedation.

Answer 84

►E The major advantage of a split-thickness skin graft over a full-thickness graft is the increased survivability. Full-thickness skin grafts have better color and texture match and less contraction. There is no significant difference in infection risk.

Answer 85

►A Catgut has a variable rate of absorption but typically lasts about 7-14 days. Thus, it would be the first suture to be absorbed. Polyglactin 910 (Vicryl) and polyglycolic acid (Dexon) are both absorbed in about 90 days. Polydioxanone (PDS) is an absorbable monofilament which lasts approximately 180 days. Polypropylene (Prolene) is not an absorbable suture.

Answer 86

►B Bupivacaine is the longest lasting injectable local anesthetic-120-240 minutes without epinephrine, 180-420 minutes with epinephrine. Lidocaine lasts 30-60 minutes without epinephrine, 120-360 with epinephrine. Mepivacaine last 45-90 minutes without epinephrine, 120-360 with epinephrine. Procaine lasts 15-60 minutes. Diphenhydramine lasts 30 minutes.

Answer 87

►B Location of tumor is an important risk factor for metastasis of squamous cell carcinoma. Compared with a 10% likelihood of metastasis for tumors located on the ear or the lip, an SCC developing in the scar, however, has been estimated to metastasize at a rate as high as 30-40%. .

Answer 88

►B Trap door deformity is believed to result from insufficient undermining. This surgical complication is most often associated with the nasolabial transposition flap. Intralesional corticosteroids may be beneficial in improving the cosmetic outcome.

Answer 89

►E According to the JAAD CME article in March 2010, cellulite is caused by the herniation of subcutaneous fat, not lipoatrophy, within fibrous connective tissue. It is prevalent in almost all postpubertal females. It is most notable in the pelvic region, lower limbs, and abdomen. The adipocytes in the gluteofemoral region are larger and are influenced by female sex hormones. They are metabolically more stable and resistant to lipolysis. The hormones that acutely affect lipolysis in adipocytes are catecholamines (epinephrine and norepinephrine) and insulin.

Answer 90

►C The Nd: YAG laser emits energy at 1064nm near the infrared range and penetrates the skin to the level of the deep dermal blood vessels. The target chromophore for this laser is melanin, thus its primary use is in treating lesions such as nevus of Ota and removing black tattoo pigment. Although both the erbium:YAG and CO2 lasers have longer wavelengths than the Nd: YAG, they are ablative lasers which only penetrate to the level of the stratum corneum and superficial epidermis, respectively.

Answer 91

►E The maximum recommended dosage of lidocaine in adults is 4.5 mg/kg without epinephrine, 7.0 mg/kg with epinephrine, and 55 mg/kg in tumescent anesthesia for liposuction.

Answer 92

►A Salicylic acid is a very superficial chemical peel that is used for acne, milia, keratolysis. This peel localizes to the pores given its lipophilic nature. It is a self-neutralizing peel.

Answer 93

►A Imiquimod (Aldara) was FDA-approved in 2004 for the treatment of superficial basal cell carcinoma. The recommended treatment schedule is once daily, five times per week for a total of six weeks. Geisse J et al. Imiquimod 5% cream for the treatment of superficial basal cell carcinoma: results from two phase III, randomized, vehicle-controlled studies.

Answer 94

►B Silver sulfadiazine is most commonly used to prevent infection in second and third-degree burn patients. Rare cases of leukopenia, neutropenia and kernicterus have been reported in patients using this topical antibacterial agent. Consequently, silver sulfadiazine should be used cautiously and avoided in infants, nursing mothers and pregnant women. Silver sulfadiazine also has the potential to cause a hypersensitivity reaction in patients with sulfa allergy.

Answer 95

►B A hemostat is shown in the photograph. This instrument is commonly used in cutaneous surgery for clamping off blood vessels.

Answer 96

►B One month after surgery with a primary closure a wound is approximately at 50% of its ultimate strength (this is 35% of the original strength of the skin). Two weeks after surgery it is at 5% strength. Three weeks after surgery it is at 20%. It never reaches 100% of its original strength, its maximum strength is 90%.

Answer 97

►C The 585nm pulsed dye laser (PDL) targets intravascular oxyhemoglobin and is considered the treatment of choice for most benign vascular lesions. The original PDL had a wavelength of 577 nm which was later modified to 585 nm to achieve deeper penetration yet still maintainvascular specificity.

Answer 98

►A To account for wound contraction and minimize the risk of ectropion, full thickness skin grafts on the lower eyelid should be sized such that the graft is at least 25% larger than the actual size of the wound.

Answer 99

►C Jessner‟s solution is a combination of resorcinol, salicylic acid, and lactic acid in ethanol that is used as a superficial peeling agent. The advantage of Jessner‟s solution is that timing is unnecessary and neutralization is not performed. The lactic acid is an alpha hydroxy acid.

Answer 100

►B Imiquimod (Aldara) is FDA-approved for the treatment of actinic keratoses and the treatment of superficial basal carcinoma. With respect to basal cell carcinoma, treatment is indicated for primary tumors that are 2.0 cm or less, and that are located on areas of the body excluding the face, scalp and anogenital region.

Answer 101

►C The carbon dioxide laser uses a 10,600 nm wavelength to target water as a chromophore. Lasers that target water may damage the cornea. The carbon dioxide laser can be used to destroy epidermal and dermal lesions such as warts. HPV virus has been recovered in the laser plume after treatment with carbon dioxide laser. Bovine papilloma virus recovered in the plume was even found to transmit disease to calf skin. Scarring and recurrence have also been found to be potential complications.

Answer 102

►D The philtral ridges are located at the upper middle lip and form part of the aesthetically important cupid‟s bow.

Answer 103

►A Alcohols exert their antimicrobials effect via denaturation of proteins ie DNA, RNA, lipids, etc. Chlorhexidine, hexachlorophene, and triclosan disrupt the microbial cell membrane. Iodine and iodophores work via oxidation/substitution for elemental form of iodine, thereby precipitating proteins.

Answer 104

►B The maximum recommended dosage of 1% lidocaine with 2.5% epinephrine in adults is 7mg/kg. The patient weighs 110 lbs (or 50 kg) which allows her 350 mg or 35 ml (1% lidocaine has 10mg of lidocaine perml) of the anesthetic.

Answer 105

►C Reticulate erythema is a recently-reported side effect of diode laser treatment. High energy fluences and a history of chilblains are believed to be predisposing risk factors. Laser treatment should be discontinued at the first sign of this complication.

Answer 106

►C Angular artery provides blood supply for the nasolabial transposition flap.

Answer 107

►E Paraphenyelenediamine is a common allergen found in permanent hair dyes. In individuals who are allergic to paraphenylendiamine, may also have allergic reactions to ester anesthetics, like benzocaine. The other answer choices are amide anesthetics. Other crossreactants to paraphenyelediamine include the preservative parabens, sulfonamides, and thiazide diuretics.

Answer 108

►D The loss and redistribution of subcutaneous fat is a characteristic finding of the aging face. The forehead, temporal fossae, malar cheeks and perioral region are the most commonly affected areas. Knowledge of senescent changes in fat distribution has altered the cosmetic surgeon‟s approach of the aging face to one which includes augmentation rather than one of simply lifting and tightening the skin.

Answer 109

►B Isolagen is an emerging technology whereby a patient”s own fibroblasts are isolated from a skin biopsy, reproduced and then re-introduced into the patient”s treatment site.

Answer 110

►B Steam autoclave is the most common type of sterilization used in the office setting. It is not to be used with heat-sensitive plastics. A negative side effect of using steam autoclave is that it can dull sharp instruments.

Answer 111

►C Serrated scissors are used primarily for gripping tissue to prevent sliding while cutting.

Answer 112

►A Electrosurgery is a broad term to describe the use of electricity to produce thermal tissue damage. Electrocautery is a method of direct heat transfer to tissue by a heated element. No electric current is transferred.

Answer 113

►E Providing hemostasis to a wound is the most important function of a wound dressing. This is particularly critical in the first few hours postoperatively when the vasoconstrictive effects of epinephrine are wearing off and the wound is at risk of bleeding or hematoma formation. The provision of a barrier to infection and creation of a moist, occlusive environment are also necessary functions of a dressing but are not as critical as immobilizing the wound and ensuring hemostasis.

Answer 114

►D Hydrogels are 70-90% water, decrease pain, provide a cooling effect, and are useful for dry and necrotic wounds. Foams are suitable for use on light-to-medium exuding wounds. Hydrocolloids ensure the moist wound environment, promote the formation of granulation tissue, and provide pain relief by covering nerve endings with both gel and exudate. Large quantities of alginates are used each year to treat exudating wounds, such as leg ulcers, pressure sores, and infected surgical wounds.

Answer 115

►C Q-switched lasers can be effectively used to remove tattoos. However, immediate darkening of white, flesh colored, and pink/red tattoos has been reported after treatment with Q-switched lasers. Both ferric oxide and titanium dioxide (found in tattoo pigments) may be both be reduced after heating by the laser and produce dramatic darkening.

Answer 116

►C Although hyaluronic acid is believed to be inert in humans, rare reports exist of granulomatous foreign body reactions to this material. Skin biopsy of a Restylane nodule demonstrates multinucleated giant cells surrounding a blue amorphous material.

Answer 117

►B In lower eyelid reconstruction, tension should be oriented parallel to the lower eyelid to prevent the development of ectropion. Secondary intention would be the least appropriate management option in this location because normal wound contraction would increase the risk of ectropion.

Answer 118

►C Dermabrasion is the process of surgically planing or abrading the epidermis and dermis and is usually carried out with a rapidly rotating wire brush or diamond fraise. Following dermabrasion, reepithelialization from adnexal structures occurs with remodeling and replacement of collagen bundles in the papillary and reticular dermis. This can result in improvement of surgical or acne scars. When used in the post-operative period for surgical scars, dermabrasion is usually carried out 6 to 8 weeks following the procedure. Regional dermabrasions are routinel y carried out under local anesthesia. Post-procedure complications include scarring, pigmentary alterations, persistent erythema, and infection. Contraindications for dermabrasion include recent use of isotretinoin and recent facelift, browlift or other procedure involving extensive undermining. Reactivation of herpes labialis can be prevented in the lip area by administering antiviral prophylaxis.

Answer 119

►E Although the procerus and orbicularis oculi muscles are contributory, the development of vertical glabellar frown lines is mostly due to the overactivity of the corrugator supercilaris. These muscles function to pull the eyebrow inferomedially. procerus muscle contraction contributes largeley to the transverse rhytides along the nasal root. Orbicularis oculi contraction contributes to crow's feet rhytides radiating from lateral canthal region. Depressor superciliaris muscle pulls the eyebrow inferomedially and partially contributes to vertical glabellar frown lines but not as much as the corrugators.

Answer 120

►E Alpha-hydroxy acids are naturally occurring carboxylic acids found in many foods. The alpha hydroxy acids include glycolic, lactic, malic, citric, and tartaric acids. Factors that determine the intensity of the peel include the concentration of the acid, pH, degree of buffering, vehicle formulation, frequency of application, conditions of delivery, and the length of time the acid is placed on the skin. Salicylic acid is a type of beta-hydroxy acid.

Answer 121

►C Ectropion occurs when the eyelid margin turns outward away from the eye. In lower eyelid reconstruction, tension should be oriented parallel to the lower eyelid to prevent the development of ectropion.

Answer 122

►E Treatment with the nonablative 1064-nm Q-switched Nd:YAG provides significant improvement in skin topography in patients with atrophic acne scars. The further improvements that are seen at 6- month follow-up suggest that dermal remodeling is a process that continues long after treatment. Reference: Maluki AH, Mohammad FH. Treatment of atrophic facial scars of acne vulgaris by Q- Switched Nd:YAG (Neodymium: Yttrium-Aluminum-Garnet) laser 1064 nm wavelength. J Cosmet Laser Ther. 2012 Oct;14(5):224-33. PMID: 23016531

Answer 123

►C The columella is one of the cosmetic subunits of the nose. It is formed by the medial crura of the alar cartilage. The nasal ala forms the free margin on the lateral inferior portion of the nose and the superior aspect of the nostril. The soft triangle is located on the inferior nose and is bordered by the ala laterally, the nasal tip superomedially, and the columella inferomedially. The philtral ridge is a paired structure located on the upper cutaneous lip. The nasofacial sulcus separates the nasal sidewall from the medial cheek bilaterally.

Answer 124

►C The lower lip has such great elasticity that full-thickness lesions that involve up to 1/3 of the lip can be excised and repaired primarily with excellent cosmetic and functional results. This type of repair requires a three layered closure of mucosa, skin and muscle. Larrabee W. In: Principles of Facial Reconstruction. Lippincott-Raven: Philadelphia, 1995; 182-183.

Answer 125

►A Electrocaogulation is set on AC, bipolar, low voltage, and high amp. All the other ones do not fit the description.

Answer 126

►C The use of follicular-unit grafts, which contain one to four hair follicles, represents the advancement in both surgical technique and aesthetic outcome in the field of hair transplantation. The grafted hair follicles typically begin to grow within 8 to 10 weeks of implantation and are expected to survive for the individual”s lifetime.

Answer 127

►B The first signs of lidocaine toxicity are CNS symtpoms that resemble inebriation with alcohol. These symptmoms include stupor, dysarthria, circumoral numbenss and dizziness. Further increases in toxicity leads to nausea, metallic taste, twitching, and seizures. Ototoxicity is not one of the toxic manifestations seen with lidocaine toxicity. Without epinephrine the maximum dose of lidocaine 4mg/kg. For a 70 kg individual, this is 300 mg or 30 ml of a 1% lidocaine solution. For a preparation of lidocaine with epinephrine the maximum dose is 7mg/kg. For a 70 kg individual, this is 500 mg or 50 ml of a 1% solution.

Answer 128

►C In the region of the temple, lateral to the eyebrow, the temporal branch of the facial nerve lies in the superficial fascia. Once above the eyebrow, the nerve is located deep to t he frontalis muscle. In the region of the temple, it is therefore prudent to undermine in the superficial subcutaneous fat.

Answer 129

►B Paradoxic darkening of flesh-tone, red, and white tattoo inks with QSRL, Q-switched Nd:YAG, and Q-switched alexandrite lasers has been reported. The tattoo pigments most associated with this phenomenon are iron oxide and titanium dioxide. Ferric sulfide is converted to ferrous sulfate by the laser.

Answer 130

►B An advancement flap is one that moves almost entirely in one direction or in a linear fashion. Rotation flap alters the direction of major closure tension forces. Transposition flap redirects and redistributes tension. Rhombic and bilobed flaps are both examples of transposition flaps.

Answer 131

►E Jessner's is a superficial peeling agent, which may be used to treat dyschromia and texture abnormalities. TCA and glycolic acid are not ingredients in this formulation.

Answer 132

►E The principle concept of chemical peeling is to utilize a chemical agent to produce a controlled wound in the skin. Many different types of side effects can occur with chemical resurfacing and are typically related to the depth of the wound. Complications which are common to all peeling agents include: milia; acne; pigmentary changes; contact dermatitis; scarring; infection; prolonged erythema; textural changes and cold sensitivity. Unlike other peeling agents, phenol has the potential to cause severe adverse reactions which are exclusive to its use only. They include atrophy, cardiac arrhythmias and laryngeal edema.

Answer 133

►C The Aptos subdermal suspension thread technique is a minimally invasive procedure which targets the ptotic changes seen with facial aging. 2-0 and 3-0 polypropylene threads are tunneled in the dermis to lift and suspend the skin and subcutaneous tissue.

Answer 134

►C While various malignancies have a predilection for metastasis to the scalp where they can cause hair loss, alopecia neoplastica is most commonly associated with metastatic breast carcinoma.

Answer 135

►E All organ transplant recipients are at increased risk for the development of cutaneous malignancies. However, the above-mentioned factors, with the exception of choice E, place these individuals at further risk. CD4 lymphocytopenia, rather th an CD8, is another identified risk factor as is older age, history of actinic keratoses and history of skin cancer.

Answer 136

►A A Z-plasty is a transposition flap used most commonly in the treatment of contractures and scars. The main advantages to performing a Z-plasty are to decrease the tension on a wound, change the orientation of a scar, and camouflage a scar by breaking it up into smaller components.

Answer 137

►B Silk is a natural nonabsorbable suture used mainly for eyelid, lip, or intraoral surgeries as they are more comfortable to the patient on these surfaces. This suture has excellent handling as it is less stiff and flows easily through soft tissue. However, it has high tissue reactivity, low tensile strength, and is associated with a higher risk of infection.

Answer 138

►A On the average, a full-thickness graft may contract by about 15% when removed from a donor site.

Answer 139

►B Artecoll is a non biodegradable injectable filler composed of microspheres of polymethylmethacrylate which are suspended in bovine collagen. As with other types of injectable bovine collagen, patients must be tested for allergy to bovine collagen prior to treatment.

Answer 140

►E Cadmium sulfide produces a yellow tattoo. Phototoxic reactions are most commonly caused by cadmium sulfide tattoo pigment. Red tattoos have also been associated with phototoxic tattoo reactions. However, this is thought thought to be due to the addition of cadmium sulfide which enhances and brightens the red color.

Answer 141

►E Croton oil is considered the most important component for efficacy. It is a epidermolytic that enhances penetration. A Baker Gordon peel is a deep peel that contains 88% phenol, tap water, croton oil, and septisol.

Answer 142

►E While regional nerve blocks offer many advantages in cutaneous surgery, hemostasis is not one of them. Since the anesthetic is injected distant to the operative site, the vasoconstrictive effects of the epinephrine, and hence hemostasis, are not provided at the surgical site.

Answer 143

►C Relaxed skin tension lines are creases in the skin that are present at rest and develop as a consequence of the decreased elasticity that occurs with aging and solar damage. These lines lie perpendicular to the underlying musculature and can be accentuated by smiling or frowning. An undermined circular wound will often form an oval shape due to muscular tension, and will have its long axis oriented within these relaxed tension lines. Knowledge of RSTLs is important in cutaneous surgery because placing incisions within these lines will ensure the most favorable cosmetic result.

Answer 144

►B Needles are either straight or curved. Curved needles have their curvature described either as a fraction of a circle or a compound curve. The greater the fraction of a circle, the more pronation and supination of the wrist required by the surgeon to place the needle. The 3/8 circle needle is easy to use in large, superficial areas and is the most commonly used needle for cutaneous surgery.

Answer 145

►C The supratrochlear, supraorbital and infratrochlear nerves are branches of the ophthalmic division of the trigeminal nerve, supplying sensory innervation to the face. The supratrochlear nerve exits the orbit approximately one centimete lateral to the midline and traverses upward along the medial supraorbital rim along the supratrochlear notch. It provides sensory innervation to the medial upper eyelid and glabella, the medial anterior forehead, and the scalp. The supraorbital nerve supplies the lateral forehead and scalp as well as the upper eyelid. The infratrochlear nerve provides sensory innervation to the root of the nose and to portions of the medial canthus. The facial nerve provides motor innervation to muscles of the face. The temporal branch of the facial nerve supplies motor innervation to the upper orbicularis oculi and the frontalis muscle, as well as the anterior and superior auricular muscles. The zygomatic branch of the facial nerve provides innervation to the inferior portion of the orbicularis oculi, zygomaticus minor and zygomaticus major muscles, as well as levator labii superioris.

Answer 146

►B In-transit metastases is a common manifestation of metastatic disease.

Answer 147

►A Coagulation/Inflammation, tissue formation, and scar/remodeling are the three phases important in wound healing. Collagen deposition occurs during the second phase. Fibroblasts migrate into the wound along the fibrin-fibronectin matrix deposited in the initial clot. The fibroblasts subsequently produce type I and III collagen, elastin, and proteoglycans. Collagen type III is the predominant collagen in early wound healing.

Answer 148

►E The cosmetic unit are based on their similarity in texture, color, solar exposure, hair density, and sebaceous features. They are not from eccrine features.

Answer 149

►A Radiesse is an injectable, biodegradable filler composed of calcium hydroxyapatite microspheres. It is a normal constituent of bone and is therefore biocompatible. Current studies are examining the role of hydroxyapatite in augmenting the craniofacial skeleton.

Answer 150

►D The snap test determines the laxity of the lower eyelid. It should be performed prior to surgery, laser resurfacing or Botox injections of the lower eyelid to assess the potential for ectropion formation. Ratner D et al. Cutaneous laser resurfacing. J Am Acad Dermatol 1999; 41(3):365389.

Answer 151

►B Bupivacaine is an amide type of local anesthetic. Its duration of action is approximately 3-5 hours and is the longest one listed. Following bupivacaine is mepivacaine, lidocaine, and procaine. The duration of action is based on the amine portion of the molecule.

Answer 152

►A Chlorhexidine or hibiclens can cause keratitis and allergic reaction if used directly in contact with the eye. It can cause ocular keratitis. It can also cause tympanic membrane damage.

Answer 153

►E Indications for healing of full-thickness skin wounds by secondary intention include infected wounds, patients who refuse reconstructive surgery or who are poor surgical risks for reconstructive surgery, and resection of tumors with high rates of recurrence. In addition, second intention, or granulation, can be utilized when the cosmetic result is anticipated to be superior or equal to reconstruction. Disadvantages of healing by granulation include prolonged wound healing time and somewhat unpredictable cosmetic results. Anatomic sites lending themselves best to second intention healing, with excellent results, are the concave areas on the face. These include the medial canthus, the nose-cheek junction, the auricular concha, the preauricular cheek, and the retroauricular scalp. The nasal tip, malar cheek, chin and forehead are all convex surfaces on the face.

Answer 154

►A Protoporphyrin IX is the substrate for the final rate-limiting step of heme synthesis. This enzymatic reaction is catalyzed by ferrochelatase. The preferential uptake of aminolevulinic acid by cancerous and pre-cancerous cells results in higher concentrations of protoporphyrin IX. This can then be selectively targeted by photodynamic therapy.

Answer 155

►A Some delayed type hypersensitivity reactions may lead to pseudolymphoma, most commonly caused by red tattoo pigment (mercuric sulfide).

Answer 156

►B This patient had a Mustarde flap, a rotation flap from the lateral canthus or cheek that close the lower eyelid or infraorbital defect. A Rieger flap is a dorsal nasal rotation flap with backcut at the glabella; it is also knows as a hatchet flap or glabellar turn-down flap. O to Z is a double rotation flap. A bilobed is a transposition flap most often used on the nose. Finally, and Abbe flap, or a lip- switch flap, is a lower lip flat of mucosa, muscle, skin, and subucutis that is transposed superiorly to the repair an upper lip defect based on inferior labial artery blood supply.

Answer 157

►B Rapamycin (also called sirolimus) is a macrolide antibiotic and a structural analog of FK 506. It is a potent immunosuppressive agent which inhibits mTOR (a member of P13K family kinases). Despite its immunosuppressive effects, preliminary data show a decreased incidence of skin cancer in organ transplant patients treated with rapamycin and postulate that it may exert a protective effect against cutaneous malignancies.

Answer 158

Relaxed skin tension lines (RSTLs) are creases in the skin that are present at rest and develop as a consequence of the decreased elasticity that occurs with aging and solar damage. These lines lie perpendicular to the underlying musculature. They tend to run diagonally on the upper back whereas on the central trunk, they are typically circumferential. Knowledge of RSTLs is important in cutaneous surgery because placing incisions within these lines will ensure the most favorable cosmetic result.

Answer 159

►D Sensory innervation of the ear is provided by the greater auricular nerve, the auriculotemopral nerve, the lesser occipital nerve and the auricular branch of the vagus nerve. The greater auricular nerve is composed of the C2 and C3 branches of the cervical plexus and lies in the posterior triangle of the neck. It provides sensation to the helix, antihelix, antitragus, posterior auricle and the lobule. The spinal accessory nerve is a motor nerve which innervates the trapezius muscle. This nerve is also subject to injury in the lateral neck but would cause motor deficits rather than sensory deficits.

Answer 160

►E The island pedicle flap is a type of advancement flap commonly used for medial ch eek defects. The closure can often be camouflaged in the melolabial fold.

Answer 161

►C Full thickness skin grafts have more adnexal structures, vessels, and structures to supply. Therefore, they are more prone to necrosis. However, they are less prone to contraction, alopecia, hypohidrosis, and hypopigmentation for similar structural reasons.

Answer 162

►C Treatment of benign vascular lesions with the pulsed dye laser often produces significant postoperative purpura. Topical vitamin K has been shown to decrease the severity of laser induced purpura although its mechanism of action has yet to be determined. No other cosmetic effects of topical vitamin K have been proven to be statistically significant. Topical vitamin K has not been show to reduce the apperance of pigmentation or telangiecatasia in any meaningful way. Additionally, it has no demonstrable effect on collagen synthesis or kerainocyte differentiation.

Answer 163

►D The carbon dioxide laser operates at a wavelength of 10,600 nm and targets water as a chromophore. Because of the high water content of the cornea, it may be damaged by exposure to irradiation from the carbon dioxide laser. Exposure to the erbium may cause corneal damage as well.

Answer 164

►E Bunny lines are located on the dorsum of the nose and are formed by the contraction of the nasalis muscle. Marionette lines form at the lateral oral commissures and run inferolaterally toward the jawline just over and lateral the region of the depressor anguli oris muscle. Crows feet lines radiate from the lateral canthal region and are caused by the orbicular oculi contraction. Nasolaial foles run from the apical triangle of the upper cutaneous lip down lateral to the oral commissures and are caused by dynamic facial muscle movements and fat pad atrophy over time. Relaxed skin tension lines run perpendicule to underlying muscle orientation.

Answer 165

►A The Shaw scalpel provides the ability to cut through tissue with minimal blood loss. This instrument employs an elctronically heated metal cutting balde that heats up while it cuts through tissue, and coagulates fine vessels when they are divided. This instrument has been used frequently for treatment of rhinophyma and in parotid gland surgeries.

Answer 166

►A The term cosmetic unit is used to define regions of the face by specific characteristics such as color, texture, presence of hair, and prominence of sebaceous glands. In dermatologic surgery, it is preferable to conceal incisions within the boundary lines of cosmetic units. In addition, moving skin from one cosmetic unit to another should be avoided when possible to minimize the appearance of apposed skin of dissimilar quality.

Answer 167

►A Wide undermining of the primary defect can release tension and prevent tenting or the trap door deformity of the flap.

Answer 168

►C Full-thickness skin grafts (FTSGs) depend upon a viable, vascular bed at the recipient site in order to survive. Exposed cartilage is an avascular tissue and therefore would not be able to support the metabolic requirements of a FTSG.

Answer 169

►A Five year cure rates of basal cell carcinomas (BCC) treated with MOHS is about 99%. The other options listed range from 90-92% five year cure rates.

Answer 170

►D The angular artery is a branch of the external carotid artery. It arises from the facial artery and courses superiorly along the nasofacial angle until it reaches the area of the medial canthal tendon. At this location, the angular artery anastamoses with the dorsal nasal branch of the ophthalmic artery establishing a communication between the internal and external carotid arterial systems. In regards to dermatologic surgery, it is important to be aware that the internal carotid artery branches into the supraorbital, supratrochlear, infratrochlear, and dorsal nasal arteries to provide blood to the central face.

Answer 171

►D The Z plasty, Bilobed, Rhombic, nasolabial flaps are all examples of transposition flaps. In each of these, the flap is transposed over a normal piece of skin to be placed in the recipient site. Whereas, the A to T flap, is an advancement flap, in which tissue is moved in a linear direction to cover the defect.

Answer 172

►C Tissue remodeling allows the host to develop a scar that is approximately 70% of the original strength of the skin.

Answer 173

►A Benzocaine, an ester, should be used as it is the only anesthetic mentioned above that is metabolized by plasma cholineseterase and then is excreted by the kidney and not the liver.

Answer 174

►B Deoxycholic acid is a detergent that dissolves fat. It is ATX-101.

Answer 175

►A Silk is a nonabsorbable braided suture which has been shown to aid in the production of infection. It is believed that the interstices of braided or twisted suture materials enhance the potential for developing infection by providing privileged sites which harbor bacteria.

Answer 176

►D Silicone is a synthetic, viscous compound which is composed of long polymers of dimethylsiloxanes. Silikon-1000 is one silicone product which is available in the United States and is FDA-approved for the ophthalmic treatment of complicated retinal detachment. The number 1000 refers to the product”s viscosity which is measured in centistokes. As a reference, water has a viscosity of 100 centistokes and mineral oil has a viscosity of about 350 centistokes. With respect to cosmetic applications, silicone is not FDA-approved for soft tissue augmentation. In addition to the occurrence of hypersensitivity reactions and product migration, there have been many reports of granuloma formation after silicone injection, even many years post-treatment.

Answer 177

►E deep peroneal nerve innervates the skin between the 1st and 2nd toes. The saphenous innervates the instep and medial ankle. The posterior tibial innervates the heel and middle sole of the foot. The sural nerve innervates the 5th toe and lateral side of the sole. The superficial peroneal nerve innervates the skin of the toes other than the outside of the 5th toe and in between the 1st and 2nd toes.

Answer 178

►D The development of vertical glabellar frown lines is due to the overactivity of the orbicularis oculi, procerus and corrugator supercilaris muscles. These muscles function to pull the eyebrow inferomedially.

Answer 179

►C Festooning of the lower eyelid is a recently reported complication of infraorbital Botox injections. The affected patient had a prior lower lid blepharoplasty which likely weakened the orbicularis oculi muscle. The author postulates that festooning resulted from further muscle weakness due to Botox treatment.

Answer 180

►A Local anesthetics like lidocaine contain 3 principle structural elements. The aromatic ring determines the onset of activity, the intermediate chain defines the class (amide vs. ester), and the amine end is responsible for the duration of action.

Answer 181

►B Botulinum toxin type A is FDA approved for the treatment of glabellar wrinkles. Botulinum toxins act by a three step process of binding, internalization by receptor medicated endocytosis and enzymatic activation. It has specific light chain intracellular binding sites and different sites of action on different SNARE (synaptosomal associated protein receptor [SNAP]) proteins. The SNARE proteins are intimately involved in releasing acetylcholine at presynaptic terminals. Botulinum toxin A cleaves SNAP-25 whereas B cleaves synaptobrevin.

Answer 182

►B Many factors contribute to the aggressive behavior of cutaneous squamous cell carcinoma. For example, tumors in immunosuppressed patients and tumors with the histologic subtypes desmoplastic and acantholytic are often biologically aggressive squamous cell carcinomas. Compared with other risk factors, depth of invasion >4 mm and size > 2cm demonstrate the greatest risk for metastasis.

Answer 183

►D The term cosmetic unit is used to define regions of the face by specific characteristics such as color, texture, presence of hair, and prominence of sebaceous glands. In dermatologic surgery, it is preferable to conceal incisions within the boundary lines of cosmetic units. The mental crease, as demonstrated in the photograph, divides the cutaneous lip and chin.

Answer 184

►A Based on the histopathologic classification and location, this infiltrative basal cell carcinoma (BCC) is best treated with MOHS surgery to preserve normal tissue and structure. 5-fluorouracil cream is used to treat superficial BCC, squamous cell carcinoma in situ (SCCIS), and actinic keratoses. Electrodessication and curettage is used to treat SCCIS and superficial BCC. Standard excision would be possible if preservation of normal tissue and structure were not as crucial as in this area, the nasal ala. Imiquimod is used to treat actinic keratoses and superficial basal cell carcinoma.

Answer 185

►E Fractional photothermolysis utilizes an infrared laser to create thousands of microthermal zones with normal skin remaining between these zones. The zones of normal skin support rapid reepithelialization and result in much faster healing times than with traditional resurfacing procedures.

Answer 186

►E All of the following are considered danger zones of the face except for the anterior aspect of the jaw where the angular artery crosses the jaw. The angular artery is most dangerous when it courses near the nose.

Answer 187

►C Injury from lasers may occur via direct or indirect ocular exposure. Damage is generally wavelength specific. Laser that target hemoglobin or pigment may cause damage to the retinal pigment or vasculature while lasers that target water as a chromophore (carbon dioxide and erbium) can damage the cornea.

Answer 188

►D Atypical mycobacterial infections are occurring with increasing frequency after cosmetic surgery procedures. These infections typically occur 4-14 weeks after a procedure as a late-occurring complication. Firm nodules at the treatment site or dehiscence of a previously healed wound may be presenting signs of atypical mycobacterial infection.

Answer 189

►A -40 to -50 “C is the temperature required in the treated skin to effectively destroy basal cell and squamous cell skin cancers. To treat malignant skin lesions a thermocoupling device can be used to measure the exact temperature of the skin while freezing. After anesthetizing the skin, this device is inserted into the estimated depth of the skin lesion. Cryotherapy is then performed until the thermometer reaches a temperature of approximately -50 degrees Celsius. Keratinocytes need to be frozen to -50 degrees Celsius for effective destruction, while melanocytes are destroyed at 5 degrees Celsius. To treat cutaneous malignancies,-50 Degress Celsius is the effective temperature. For benign skin lesions such as verrucae, -20 degrees Celsius is effective.

Answer 190

►B Branches of the internal carotid artery include the ophthalmic artery, supraorbital artery, dorsal nasal artery, supratrochlear artery, palpebral artery, and lacrimal artery. Branches of the external carotid artery include the superficial temporal artery, facial artery (inferior labial, superior labial, angular branches), maxillary artery, posterior auricular, and occipital artery. The external and internal carotid arteries anastamose in the periorbital region.

Answer 191

►E Research into the preventive role of topical antioxidants in photoaging is based on the free radical theory of aging. All of the choices above are antioxidants which are naturally found in the skin, however, alpha-tocopherol is the major antioxidant in human epidermis. Epidermal depletion of this vitamin has been shown to be an early and sensitive marker of environmental oxidative damage.

Answer 192

►D Cytokeratin 7 is a structural component of the cytoskeleton that stains poorly differentiated tumors of the epithelium. This low molecular weight cytokeratin positively stains Paget cells. Neuron- specific enolase stains merkel cell carcinoma, toluidine blue stains mast cells and myeloperoxidase stains cells with myeloid differentiation such as leukemia cells. S -100 protein is a non-specific stain that is commonly used as an adjunctive marker in the diagnosis of melanoma.

Answer 193

►C Glogau‟s photoaging scale is a classification system that employs clinical markers of photodamage to determine an individual‟s level of photoaging. The scale ranges from Type 1 through Type 4, with Type 4 demonstrating the most extensive photodamage. Type 3 on the Glogau scale is classified as advanced photoaging and describes a patient who is typically 50 years of age or older, has wrinkles at rest, telangiectasias, obvious dyschromias and visible keratoses.

Answer 194

►C Collimation is the parallel nature of coherent light waves. Monochromaticity is the emission of a single wavelength. Coherence is the term for light waves traveling in phase. Energy is the fundamental unit of work. Power is the rate of energy delivery measured in watts. c

Answer 195

►D Sculptra (called New-Fill outside of the US) is a biodegradable filler composed of poly-L-lactic acid, the same material used in absorbable sutures. It is biocompatible and nonallergenic and was approved by the FDA in August 2004 for the treatment of HIV-associated lipoatrophy.

Answer 196

►D Beta blockers increase lidocaine levels. The rest of the answers are false. 1% lidocaine is equal to 1g/100ml or 10mg/ml. Duruation of lidocaine with no epi is 30-60 minutes. Maximum dose of lidocaine with no epi is 4.5 mg/kg, with epi it is 7 mg/kg. Allergy to lidocaine is most commonly due to paraben preservatives.

Answer 197

►A Electrocautery is the only one to work in a wet field as it has no current and works via heat.

Answer 198

►B The maximum dosage of lidocaine is 4.5 mg/kg without epinephrine and 7.0 mg/kg with epinephrine. Signs of lidocaine toxicity start at 1-5 microgm/ml with increased anxiety, talkativeness, tinnitus, numbess/tingling around lips, metallic taste, double vision. Higher levels of toxicity may cause nystagmus, muscle twitching, tremor and finally seizures and respiratory arrest.

Answer 199

►B The procerus muscle causes wrinkling at the nasal root and is often targeted with Botox therapy for improved cosmesis.

Answer 200

►D The auriculotemporal nerve which is a branch of the mandibular branch of the trigeminal nerve innervates the tragus. The sensory innervation to the auricle is provided by the greater auricular nerve, and to a lesser extent the lesser occipital nerve. The external auditory canal, concha, and posauricular sulcus supplied variably by 3 nerves - the auricular branch of the vagus (CNX), the facial nerve (CN7), and the glossopharyngeal (CNIX).

Answer 201

►C Polymyxins are peptides produced by the organism Bacillus polymyxa. They are bactericidal against Pseudomonas aeruginosa, Proteus mirabilis, Enterobacter, Klebsiella and Escherichia coli. Since they provide little coverage against gram-positive organisms, polymyxins are often combined with other antibacterial agents to increase their spectrum of activity. Mupirocin covers gram positive organisms mostly, including MRSA, but many reports of resistance are emerging. Topical bacitracin and clindamycin also cover almost exclusively gram positive organisms. Erythromycin has some gram negative (less than gram positive) organism coverage, but does not reliably treat pseudomonas.

Answer 202

►C Solid media lasers include alexandrite, KTP, ruby, Nd Yag, diode. Liquid media is found in the pulsed dye laser. Gas media is used in argon, carbon dioxide, krypton, and cooper vapor laser.

Answer 203

►D The most serious adverse effect of eutectic lidocaine and prilocaine (EMLA) is methemaglobinemia. A metabolite of prilocaine oxidizes hemoglobin to methemoglobin, which is less efficient in release of oxygen leading to tissue hypoxia. Patients with congenital or idiopathic methemoglobinemia or infants under 1 year of age are at higher risk for the development of this side effect.

Answer 204

►B Homocysteine is a sulfhydryl-containing amino acid produced during the conversion of methionine to cysteine. Homocysteine can promote defects in fibrillin-1 and stimulate matrix metalloproteinase production, leading to collagen and elastic fiber degradation. Homocystinuria, caused by a deficiency in cystathionine beta-synthase, presents with osteoporosis, thin skin, and striae. Alpha- tocopherol, beta carotene, proacanthocyanidin, and alpha-lipoic acid have all be described to slow the aging process of the skin via multiple mechanisms including decreasing the inflammatory response and reducing free radical damage.

Answer 205

►A Laser light is monochromatic light that is emitted at a single wavelength. The wavelength of the laser is determined by the medium in the optical cavity of the laser through which the light passes. The medium may be solid, liquid or gas. Fluence and pulse duration affect the energy delivered by a laser. Spot size influences depth of penetration. Lens length does not influence the wavelength of a laser.

Answer 206

►E The erbium (2940 nm) and carbon dioxide (10,600 nm) lasers may both cause milia formation after laser skin resurfacing.

Answer 207

►C Radiesse is an injectable, biodegradable filler which is composed of calcium hydroxylapatite microspheres. Calcium hydroxylapatite is a normal constituent of bone and thus can be seen on radiographic imaging. Botox is botulinum toxin; Zyplast is bovine collagen; Cosmoderm is a non- animal form of collagen; and Restylane is a non-animal form of hyaluronic acid.

Answer 208

►A A Z-plasty is a type of transposition flap that may be used to reorient a scar, especially when the scar crosses skin tension lines. It is also used to change the scar length or vector and ease scar contractures.

Answer 209

►E Restylane is a hyaluronic acid gel produced by the Streptococcus species of bacteria. The package insert for Restylane warns that its use is contraindicated in patients with “severe allergies manifested by a history of anaphylaxis or the presence of multiple severe allergies”.

Answer 210

►D Antibiotics are usually given 60 minutes prior to the procedure. The American Heart Association advises it can be given up to 2 hours after the procedure if not given before. Infections are usually polymicrobial, but staph and Strep are of prime concern.

Answer 211

►E E Melan-A is a 22-kDa cytoplasmic melanosome-associated glycoprotein also known as MART1 (melanoma antigen recognized by T cells). It is a sensitive marker for both melanocytic nevi and melanoma and may be used on frozen tissue sections as well as paraffin-embedded tissue. Although the antigen is present in > 80% of melanomas, it does not reliably stain desmoplastic or spindle cell melanomas.

Answer 212

►E Preoperative antibiotics are recommended for endocarditits prophylaxis in select high risk patients that undergo high risk procedures. High risk procedures are procedures that involve manipulation of gingival tissue or the periapical region of teeth or perforation of the oral mucosa. High risk patients are, according to the guidelines, those with the following: Prior infective endocarditis, Prosthetic cardiac valves, Unrepaired cyanotic congenital heart defects, including palliative shunts and conduits Congenital heart defects completely repaired with prosthetic material or a device, whether placed by surgery or by catheter intervention, during the first 6 months after the procedure, Repaired congenital defects with residual defects at the site or adjacent to the site of a prosthetic patch or prosthetic device, Cardiac transplants and development of cardiac valvulopathy. Patient groups that may have received routine antibiotic prophylaxis in the past but are no longer candidates for it include those with mitral and aortic valve disease, rheumatic heart disease, or structural disorders like ventricular or atrial septal defects or hypertrophic cardiomyopathy, according to the AHA statement. The revised guidelines were developed with the participation of and have been endorsed by the American Dental Association, the Infectious Diseases Society of America, and the American Academy of Pediatrics. Classically 1 gram of Dicloxacillin or cephalexin is given 1 hour preoperatively and an additional 500 mg is given 6 hours post op. Clindamycin can be givenin those patients who are penicillin allergic.

Answer 213

►C Imiquimod is a topical immunomodulator which induces the toll like receptor 7 and is used in the treatment of genital warts, actinic keratoses, and superficial basal cell carcinomas. It has a newly reported side effect of eruptive epidermoid cysts. Minocycline has side effects including a lupus-like syndrome and hepatitis. Retinoids has numerous side effects including hypertriglyceridemia, elevated liver enzymes, dryness of skin, teratogenicity, and most recently inflammatory bowel disease. Denileukin difitox, an engineered protein combining interleukin-2 and Diphtheria toxin, used in mycosis fungoides may cause vascular leak syndrome characterized by hypotension, edema, and pleural effusion. Potassium iodide may lead to the Wolff-Chaikoff effect in which thyroid hormone synthesis is inhibited from excess iodides that block organic iodides from binding in the thyroid.

Answer 214

►D Imiquimod is an immunomodulator which induces the production of cytokines that are involved in cell-mediated immunity. These cytokines include interferon-alpha, interferon-gamma, interleukin-1, interleukin-10 and tumor necrosis factor-alpha. Induction of these cytokines results in antiviral and antitumor activity in vivo.

Answer 215

►A The O to Z flap is a bilateral rotation flap in which tissue is moved from two ends to cover a central defect. It is often used on the scalp or lower extremities in locations where tissue laxity is not present.

Answer 216

►C Botulinum A exotoxin is used for multiple reasons, most often for the treatment of dynamic facial lines. In a double-blind, randomized controlled study, investigators found that botulinum A exotoxin reconstituted with preservative-containing saline less painful than with preservativefree saline.

Answer 217

►B The nasalis muscle is responsible for the foreshortening of the nose. It is responsible for the 'bunny lines."

Answer 218

►C Organ transplant recipients are at risk for developing many cutaneous tumors. The risk of melanoma is 3-fold that of the general population whereas these patients have a 65-fold increased risk of developing squamous cell carcinoma.

Answer 219

►B Sutures are classified according to the United States Pharmacopeia (USP) criteria. This classification system specifies the diameter of a given suture material that is required to produce a certain tensile strength. The smaller the cross-sectional diameter of a suture material, the higher the USP number that is assigned. Thus, 4-0 Vicryl will have greater tensile strength and a larger cross-sectional diameter than 5-0 Vicryl.

Answer 220

►C An M-plasty is a variation of the fusiform excision where either one or both ends of the ellipse are modified. The main advantages to performing an M-plasty are to shorten the length of an excision and to correct dog-ears.

Answer 221

►B Procaine has the shortest duration of action, only lasting about 30-60 minutes. It is an ester anesthetic and is commonly used in dentistry.

Answer 222

►A Hexachlorophene should not be used in children or in pregnant women. It has a potential for neurotoxicity and can be teratogenic.

Answer 223

►E The carbon dioxide laser is a 10,600 nm laser that can be used to treat rhinophyma. The advantage of the carbon dioxide laser over steel or dermabrasion is that the laser is relatively bloodless. The erbium YAG can also be used to treat rhinophyma.

Answer 224

►A Allergic reactions have been reported with several different types of tattoo pigment. The most commonly associated tattoo pigment however is mercuric sulfide. Tattoo with mercuric sulfide produces a red color.

Answer 225

►C M-plasty is used to shorten wound length and is often when it is not desirable to extend the ellipse into a nearby structure. This becomes important when reconstructive efforts lie adjacent to important nearby free margins or cosmetic subunit junctions. M-plasty repair does not decrease the risk of post-operative bleeding or infection, nor does it lengthen the wound or decrease pincushioning in any meaningful way

Answer 226

►C Damage to the zygomatic nerve causes eyelid ectropion and inability to close eyelid.

Answer 227

►D Hexachlorophene is an antibacterial agent that was first introduced in 1944. Its use was discontinued in the 1970s when it was discovered to have neurotoxic side effects.

Answer 228

►B Thermage (ThermaCool) is a nonablative radiofrequency-based system which uses volumetric heating to induce tightening of the skin and dermal remodeling. Lipoatrophy is a late -occurring potential complication of this technology.

Answer 229

►D Hexachlorophene or pHisoHex has shown to be toxic to developing embryos in animal studies and thus is prohibited for use in pregnant females. Chlorhexidine is a common ingredient in oral rinses(Peridex) and surgical prep solutions(Hibiclens) can cause ototoxicity if in contact with the middle ear and ocular toxicity if in contact with the eyes. Ethyl alcohol is effective against both gram positive and gram negative organisms. Both Povidine-Iodine (Betadine)and Benzalkonium chloride (Zephiran) can cause an allergic contact dermatitis.

Answer 230

►D The term cosmetic unit is used to define regions of the face by specific characteristics such as color, texture, presence of hair, and prominence of sebaceous glands. In dermatologic surgery, it is preferable to conceal incisions within the boundary lines of cosmetic units. The mental crease divides the cutaneous lip and chin.

Answer 231

►D The tensile strength of a wound approaches 70% of normal skin strength at 6 months postoperatively. Wound healing is a process which takes many months, yet the tensile strength of a wound never exceeds 80% of the tensile strength of intact skin. It is therefore critical to use long- lasting subcuticular sutures to minimize the tension on a healing wound and prevent scar widening.

Answer 232

►C The use of epinephrine with local anesthesia has two main advantages. Firstly, the epinephrine is a vasoconstrictor and assists in controlling bleeding during surgery. Secondly, and also a direct result of its vasoconstrictive effects, epinephrine helps prolong the duration of the anesthetic agent 100% to 200% by delaying its absorption from the surgical site. Although the anesthetic properties of lidocaine take effect within the first few minutes of infiltration, the vasoconstrictive effects of epinephrine require approximately 15 minutes to fully develop.

Answer 233

►E The „MCW Melanoma Cocktail‟ is an immunostain made up of monoclonal antibodies to MART-1, Melan-A and tryrosine. It is used intraoperatively during sentinel lymph node biopsy and allows for rapid and accurate determination of micrometastases. Shidham VB et al. Optimization of an immunostaining protocol for the rapid intraoperative evaluation of melanoma sentinel lymph node imprint smears with the „MCW Melanoma Cocktail‟. Cytojournal 2004;1(1):2.

Answer 234

►A As placement of bovine collagen is typically deeper in the tissues compared to other filler, its use has resulted in vascular occlusion and necrosis in the glabellar area, and is therefore contraindicated.

Answer 235

►B Sculptra (called New-Fill outside of the US) is a biodegradable filler composed of poly-L-lactic acid, the same material used in absorbable sutures. Preliminary studies have demonstrated longevity of the filler at two years post-treatment. Valantin MA et al. Polylactic acid implants (New-Fill) to correct facial lipoatrophy in HIV-infected patients: results of the open-label study VEGA. AIDS. 2003;17:2471-2477.

Answer 236

►D The use of sodium bicarbonate in 1% lidocaine reduces the acidity of the local anesthetic. Unbuffered lidocaine has pH of approximately 5.5 -7.0 and lidocaine with epinephrine has a pH of approximately 3.5 - 5.0. The addition of sodium bicarbonate at a ratio 1:10 raises the pH to a more physiologic level, thereby reducing the stinging sensation associated with injection. However, the addition of bicarbonate also reduces the shelf-life of the lidocaine.

Answer 237

►D P r i l o c a i n e s h o u l d n ’ t b e u s e d i n c h i l d r e n g i v e n t h e r i s k o f methemoglobinemia.Methemoglobulinemia in children can occur from exposure to oxidizing substances such as aniline dyes, prilocaine or pyrimidine. In methemoglobinemia, the iron in hemoglobin is oxidized from the ferrous state (Fe 2+) to ferric (Fe3+) resulting in the inability to transport oxygen and carbon dioxide. Clinically, this condition results in cyanosis.

Answer 238

►B The excimer laser is a 308 nm wavelength laser that has been used to treat psoriasis. The excimer laser has some advantages over ultraviolet therapy. By treating only involved skin, higher doses can be used and clearance may occur with fewer treatments.

Answer 239

►C Cocaine is the only anesthetic that vasoconstricts in the absence of epinephrine. Cocaine is an ester anesthetic. Full vasoconstriction effects of epinephrine requires 7 -15 minutes. Epinephrine is pregnancy category C.

Answer 240

►B Tungsten carbide is believed to be a harder more durable material that allows for better grasping of the needle. Needle holders with tungsten carbide jaws usually have gold-plated handles.

Answer 241

►C Lichenoid tattoo reactions are not as common as eczematous reactions, both of which are most commonly caused by mercuric sulfide. Lichenoid reaction are likely to be mediated by delayed hypersensitivity to a lymphocytic T-cell infiltrate.

Answer 242

►D Jessner's is a light-medium chemical peel that contains salicylic acid, lactic acid, ethanol, and resorcinol. Phenol is used in deep peels, ie the Baker-Gordon peel which also contains croton oil, water, and septisol. Phenol may induce cardiac arrythmias and liver or renal failure; hydration i s important in all phase of treatment.

Answer 243

►D Hyaluronic acid is a natural component of human connective tissue. As a cosmetic filler, hyaluronic acid is an attractive alternative to currently available filler substances: its ability to bind water creates volume and plumps the skin; its duration of action of approximately 6-12 months is appreciably longer than conventional collagen; and since hyaluronic acid is chemically identical across all species, hypersensitivity reactions are rare.

Answer 244

►D EMLA is a topical anesthetic composed of a eutectic mixture of 2.5% lidocaine and 2.5% prilocaine. The major concern when using EMLA is the potential risk of methemoglobinemia. Patients with glucose-6-phosphate deficiency and patients taking methemoglobin-inducing agents (dapsone, phenytoin, sulfonamides) are more susceptible to developing methemoglobinemia. In addition, care should be taken when using EMLA in infants less than 3 months of age because of the incomplete maturation of their NADH-methemoglobinemia reductase system.

Answer 245

►A The pulsed dye laser operates at 585-nm and targets hemoglobin as a chromophore. It can pass through the cornea and damage choroidal and retinal vasculature. Several pigment-specific lasers (eg, ruby, alexandrite, Nd:YAG) may also damage the retina by targeting the retinal pigment. The eye damage is related to the chromophore of the laser. The lasers that target water damage the cornea.

Answer 246

►B The postauricular flap is useful for repairing extensive defects of the helical rim, particularly when cartilage is involved. It is an example of an interpolation flap.

Answer 247

►E Epinephrine should be avoided in patients with a pheochromocytoma. Explanation: Absolute contraindications to epinephrine use include pheochromocytoma and hyperthyroidism. Patients with poorly controlled hypertension and severe cardiovascular disease, as well as those who are pregnant, should also be considered with caution prior to using epinephrine. Use in the periorbital area in patients with a history of narrow angle glaucoma should be avoided as well. Liver failure, renal failure, diabetes mellitus, and hypothyroidism are not contraindications to epinephrine use with anesthesia.

Answer 248

►A The rhombic flap is a type of transposition flap. The classic rhombic flap is designed with two 60 degree angles and two 120 degree angles. The point of maximum tension is at the closure of the donor site.

Answer 249

►C Thoughtful design of an elliptical excision is important for obtaining optimum tissue diagnosis, tumor clearance, wound closure and cosmetic result. The above statements are all true except that the angles at the apices of the ellipse should be 30º. A properly designed ellipse should be at least three times as long as it is wide, include the lesion of interest with proper margins, and have 30 degree apical angles. Repair of surgical defects should always attempt to: 1) maintain function 2) preserve free margins 3) respect cosmetic subunit boundaries 4) hide scar in relaxed skin tension lines.

Answer 250

►C Kovich et al. JAAD 2003 evaluated thrombotic complications in patients who had stopped either coumadin or aspirin peri-operatively. Thrombotic complications in patients who stopped warfarin included stroke, TIA, myocardial infarction, cerebral embolism, death, DVT, pulmonary embolus, and blindness. Thrombotic complications in patients who stopped aspirin included stroke, TIA, myocardial infarction, cerebral embolism and death. No DVT or pulmonary embolus was reported.

Answer 251

►C Prior to Mohs patients who are at high risk should receive prophylaxis int he form of cephalexin (or clindamycin or azithromycin if penicillin-allergic) 30-60 minutes prior to the procedures for non- oral skin. High risk patients include those with prosthetic valves, a history of bacterial endocarditis, mitral valve prolapse with regurgitation, mitral valve prolapse without regurgitation in MEN > 45 years, any valve dysfuntion, cardiac malformation, hypertrophic cardiomyoopathy, CNS shunts, and more. Some low-risk examples (no prophylaxis) include s/p CABG, pacemaker, murmur, or mitral valve prolapse without regurgitation.

Answer 252

►A UVA is known to cause photoallergic reactions. It penetrates glass and goes deep into the dermis and can cause immediate erythema.

Answer 253

►C Most common side effect seen with betadine is allergic contact dermatitis, secondary to the iodine component.

Answer 254

►B The forehead flap is often the reconstructive option of choice for large nasal defects. The flap has a vertically-oriented blood supply which is supplied primarily from the supratrochlear arteries. Pedicle division and inset of this flap are typically performed 3 weeks after the initial surgery.

Answer 255

►D Infection after cutaneous surgery is typically due to Staphylococcal and Streptococcal organisms. However, Pseudomonas aeruginosa may be normal flora of the ear and thus can potentially complicate ear surgery by causing severe infection of the external ear canal (malignant otitis externa). Ciprofloxacin would be the antibiotic of choice for this patient because it is effective against Pseudomonas species.

Answer 256

►C The wavelength of a laser is determined by the medium.

Answer 257

►B The patient shown has multiple solar lentigines. Targeting the melanosomes in these benign, superficial pigmented lesions would be most successfully accomplished with the intense pulsed light source.