SKIN EXAM & DERM PROCEDURES PPT Flashcards
GOAL OF SKIN EXAM
- determine general skin color & number of nevi
- screen for melanoma: look for lesions with ABCDE
ABCDEs of moles
Asymmetry Border irregularities Color variation Diameter > 6mm Evolution (of color, shape, symptoms) or Enlargement
hand held microscope used by dermatologists
dermatoscope
SKIN MAPPING / MOLE MAPPING
Another less commonly used method of following change with pigmented lesions is mole mapping. With this technology, suspicious moles can be digitized with dermatoscopes cameras and reimaged at three- to six-month intervals to determine if any changes in characteristics have occurred in this time
indications for a biopsy
- All suspected neoplasms
- All bullous disorders
- To clarify a diagnosis when a limited number of entities are under consideration
BEFORE DOING THE BIOPSY
Make sure patient has no absolute contraindications
Pt needs to be asked about allergies/reactions to topical antibiotics, local anesthetics and tape
Need to know if pt has a bleeding disorder or is on aspirin or warfarin
o If on aspirin—OK to biopsy; use pressure dressing
o If on warfarin—refer to dermatologist
Nerves & Vessels run in the _____________ plane; so punch biopsies can be safely performed if they are stopped at the interface of ______ & __________
subcutaneous fat
dermis & subcutaneous fat
BIOPSY DANGER ZONES
Areas overlying highly vascular structures
Areas associated with exit points of superficial motor nerves
1) lateral mandible = exit point of marginal mandibular nerve
2) posterior lateral neck = exit point of spinal accessory nerve
3) temple = temporal branch of facial nerve
SITE SELECTION FOR BIOPSY
o Inflammatory lesions - biopsy those with characteristic inflammatory changes (ex: erythema) first
o Blistering diseases - biopsy only the newest vesicles or blisters, ideally within 48 hours. Remove vesicles intact with adjacent normal skin when possible (include normal skin, border, and inner vesicle if possible for pathologist to compare)
o Nonbullous lesions
include maximal lesional skin & minimal normal skin
lesions that are between 1-4mm = excise completely
for larger lesions = biopsy the edge, the thickest portion, or the area that is most abnormal color
o Bullae = at the edge, including a small part of the blister with adjacent normal intact skin - keep the blister roof attached. Want to get some normal skin, the border, and the lesion
BIOPSY CONSIDERATIONS
- all biopsies leave scars!
- important cosmetic areas, such as the face and areas with poor healing should be avoided when possible
- when there is a lesion(s) involving cosmetic areas, it may be preferable to refer to a dermatologist or plastic surgeon
where should you NOT use epi?
fingers / toes / nose / ears / penis
derm anesthetics
Lidocaine 1%
Lidocaine 1% with epinephrine (1:100,000)
Lidocaine 2.0% + Prilocaine 2.5% (EMLA cream)
which anesthetic is useful for procedures requiring anesthesia of the fingers, toes, nose, penis, or ear
lidocaine 1%
The standard solution of lidocaine has a pH of
5-7
buffer lidocaine with ________________ which will change the pH to
sodium bicarbonate
7 - 7.2
add 1 part sodium bicarb to 9 or 10 parts lidocaine
purpose of buffering lidocaine
decrease the discomfort associated with injection and to enhance anesthetic tissue dispersion.
Useful for anesthesia in all procedures except those that involve the fingers, toes, nose, penis, or earlobes, or in patients on non-selective beta blockers
lidocaine 1% with epi
lidocaine 1% with epi = Useful for anesthesia in all procedures except those that involve the fingers, toes, nose, penis, or earlobes, or in patients on ____
non-selective beta blockers
propranolol (Inderal), nadolol (Corgard)
advantages of epi to lido
Less bleeding
Prolongs anesthetic action
Also allows for larger volumes of anesthetic to be used safely (maximum 7 mg/kg = 49 cc for 70 kg person) (normally is 4 mg/kg = 28 cc for 70 kg person)
PROCESS FOR ANESTHETIZING AREA
Draw Lido with a 16-18G needle and switch out to a 25-30 G needle to use on the pt
Small syringe: 3-5cc
Make initial injection perpendicular to the skin
Inject directly into or immediately adjacent to small lesions
Must be infiltrated into the dermis to elevate a lesion for biopsy
LOCAL BLOCK / ANESTHESIA
Slowly inject small volumes of anesthetic taking care to monitor the total dose administered.
During anesthetic infiltration, either slowly advance the needle or initially insert it to the hub, and infiltrate as the needle is withdrawn.
Reinsert the needle through the area just anesthetized, redirecting it along the margins of the wound or circumferentially around the abscess and infiltrate additional anesthetic.
Continue infiltration through previously injected skin until the entire region requiring anesthesia is infiltrated.
After a few minutes, lightly test the skin or wound margins for adequate anesthesia using the injection needle or other sharp object (suture needle, Addson forceps).
FIELD BLOCK
In the field block, anesthetic is infiltrated to the subcutaneous area surrounding the operative field.
The needle is inserted at two points, and anesthetic solution is injected along four lines (walls) that surround the area to be anesthetized
LANGER’S LINES
Round wounds tend to be pulled open in the direction of skin tension lines (Langer’s lines)
They parallel the direction of the collagen in the dermis
Surgical incisions placed parallel to tension lines will close more easily and cosmetically then those placed at a right angle
SHAVE BIOPSY INDICATIONS
Easy, no sutures, leave a small depressed scar
Lesions suitable are elevated and confined to the epidermis:
⦁ Seborrheic or actinic keratoses
⦁ Skin tags
⦁ Small superficial lesions
SHAVE BIOPSY TECHNIQUE
⦁ Elevate the lesion by injection lidocaine into the dermis
⦁ Stabilize the lesion by gently holding it w/ forceps
⦁ Using a scalpel # 15 or razor blade shave it off ; It can be superficial or deep
⦁ Hemostasis is often stopped by pressure alone
⦁ Oozing can be controlled w/ 10-20% aluminum chloride (Drysol); other hemostatic agents are Ferric subsulfate (Monsel’s solution) or silver nitrate
PUNCH BIOPSY
Uses a special tool that comes in different sizes and removes a cone shaped core of tissue
Langer’s lines should be determined first
Inject the anesthetic
Stabilize the skin w/ the thumb and forefinger, stretching it slightly perpendicular to the skin tension lines ( this produces an oval rather than a round wound)
4mm bx can usually be allowed to heal by secondary intention
Larger than 4mm need to be closed with stitches
Larger than ____mm punch need to be closed with stitches
4
EXCISIONAL BIOPSY
⦁ Direction of the lines of skin tension lines is determined after performing a field block
⦁ Draw an ellipse around the lesion to be excised including a 2-5mm margin of normal skin
⦁ The length should be 3x the width
⦁ Using a # 15 blade begin at one apex with the blade perpendicular to the skin & and start the incision
⦁ Grab the edge of the area to be excised and gently dissect the biopsy tissue out on an even plane.
⦁ Undermine the edges of the wound before closing if needed.
excisional biopsy must be deep enough to go down to the
subcutaneous fat
____________ sutures are used for the scalp because it is blue
otherwise _______________ is used
POLYPROPYLENE
monofilament nylon
CLOSING THE SITE
⦁ Usually interrupted nonabsorbable sutures are placed
⦁ For skin closure using monofilament, synthetic suture material results in less chance of infection and less inflammatory reaction
⦁ Polypropylene is used for the scalp because it is blue, monofilament nylon is otherwise used
⦁ Suture size is indicated by code 0: the more 0’s the smaller the suture diameter, 4-0, 5-0 on body, scalp, 6-0 nylon on face
_______ suture size on face
______ on body / scalp
6-0 on face
4-0 / 5-0 on body
SUTURE NEEDLES
⦁ Needle points are also defined: cutting, tapered and blunt
⦁ Cutting are ideal for easy passage through skin
⦁ A code has been developed for needles:
o FS (for skin) and CE (cutting needles) used on thick skin o P (plastic) and PS (plastic skin) used for cosmetic closures
SUTURING
⦁ Placement of sutures for elliptical excisions follows the “rule of halves”
⦁ Wound is divided in half by an initial suture and subsequently each half is itself halved until all wound edges are approximated
⦁ Excessive tension on the sutures leads to blanching of the wound edges and puckering
WOUND CARE
⦁ All biopsy wounds can be dressed with a thin film of antibiotic ointment then an adhesive bandage
⦁ Can shower in 24 hours, no baths or hot tubs until the sutures come out
⦁ Suture removal
- Face: 3-5 days
- Back and legs: 10-14 days
- Remainder of the body: 7-10 days
suture removal:
- face
- back & legs
- rest of body
face = 3-5 days
back / legs = 10-14 days
rest of body = 7-10 days
POST-OP COMPLICATIONS
o BLEEDING
⦁ usually controlled with pressure dressing & ice
⦁ suture if not sutured
o INFECTION
⦁ uncommon
⦁ staph, strep, candida
⦁ culture & start antibiotics or antifungal ointment
o Allergic Rxn to Tape
not aligning skin up properly when closing can result in
“dog ears”
WOOD’S LAMP
- When UV light is projected through Wood’s filter, the light rays have a wavelength > 365 nm
- When shown on the skin or hair in a dark room certain infections will fluoresce
⦁ Hair infected w/ Microsporum spp. (fungus) turns blue-green (20% of tinea capitis infections); not all tineas will fluoresce
⦁ Skin infected with tinea versicolor produces a pale white-yellow fluorescence
⦁ Erythrasma shows brilliant coral-red
⦁ Accentuates hypopigmented areas in vitiligo
tinea capitis from microsporum (20% of cases) shows up what color with wood’s lamp
blue-green
erythrasma shows up what color with wood’s lamp
brilliant coral-red
tinea versicolor shows up as what color with wood’s lamp
pale white-yellow
vitiligo with wood’s lamp
hypopigmented areas are accentuated
KOH SKIN SCRAPINGS
If you suspect a fungal skin infection:
⦁ Scrape some of the affected skin onto a slide – try to get as much of the specimen as possible
⦁ Add some potassium hydroxide and let sit for 10-15 min.
Examine under a microscope looking for:
⦁ Hyphae – septate (tinea corporis)
⦁ Curved (spaghetti and meatballs) tinea versicolor
⦁ Round or oval budding forms – yeast (Candida)
septate hyphae under KOH =
tinea corporis
curved hyphae under KOH (spaghetti & meatballs) =
tinea versicolor
round or oval budding forms (& hyphae)
yeast (candida)
multinucleated giant cells
HSV
TZANCK SMEAR
Confirms viral infection with HSV
Gently rupture fresh vesicle, gently scrape debris from vesicle base
Smear debris onto microscope slide
Add drops of stain (Giemsa or Wright) and allow to sit 1 minute
Rinse off stain under gently running water, add a drop of mineral oil, apply cover slip
Positive test will show Multinucleated Giant Cells
positive tzanck smear for HSV will show
multinucleated giant cells
indications for cryotherapy
⦁ Warts - may want to avoid freezing facial flat warts due to risk of discoloration
⦁ AKs
⦁ SKs
CRYOTHERAPY
- Cryo is painful so is limited to older children and adults
- Generally should pare hyperkeratotic warts down to areas of punctate bleeding prior to cryo
- Use cautiously on the digits
⦁ especially where nerves are located, to prevent severe pain and possible neuropathy
⦁ avoid over-freezing in the periungual region, which can result in permanent nail dystrophy
- SHORT TERM COMPLICATIONS OF CRYOTHERAPY
⦁ Pain is variable among individuals; however, be prepared for vasovagal reactions and do not use cryotherapy in small children.
⦁ Lesions may be painful after freezing as a result of pressure from edema caused by the blister
⦁ Hemorrhage is common. Inform patients that formation of a “blood blister’’ is normal, especially when treating thick lesions such as warts
⦁ Infection
most serious complication of cryotherapy
nerve damage
nerve damage from cryotherapy is especially likely where nerves are superficial, such as
on the sides of fingers
postauricular, or
the peroneal nerve (lateral to patella)
long-term complications of cryotherapy
⦁ Nerve damage is the most serious complication, and is especially likely where nerves are superficial, such as on the sides of fingers, postauricular, or the peroneal nerve
⦁ Pigmentary changes are common and may be especially disfiguring in darker skinned patients
⦁ Hypertrophic scar formation and tissue defects with delayed healing are possible if lesions are frozen too deeply or when freezing thick lesions
⦁ Permanent nail dystrophy may occur if a periungual lesion is frozen too deeply
⦁ Recurrence of a lesion, particularly warts, is possible
CRYOTHERAPY TECHNIQUE
⦁ Frozen areas of the skin will turn white immediately. This is referred to as the “freeze ball’’ or “iceball.’’
⦁ The depth of freeze should be roughly equal to one and one-half times the radius of the freeze ball unless the lesion is superficial, eg, solar lentigo, in which the depth of freeze is less.
⦁ To treat small papules or thin, flat lesions, freeze the lesion for 5 to 10 seconds, leaving a rim of white 1 to 3 mm around the lesion.
cryotherapy: Often the skin will quickly become edematous and “urticarial,’’ because freezing causes separation of the
epidermis from the dermis –> blister
A hemorrhagic area may develop from cryo if the lesion is frozen deeper than the
epidermis
