Derm Flashcards
Describe 10 questions of the dermatologic history
- Onset (primary lesion, timing)
- Pattern of spread
- Symptoms
- Treatments
- Medications & allergies
- PMH of skin, other
- FH for skin conditions
- Work/hobby contactants (including pets)
- Recent travel/exposures
- Sexual history
Describe the 5 components of the dermatologic physical exam
- Type of lesion; primary/secondary/special
- Distribution
- Configuration
- Color
- Epidermal (surface change) or dermal (no surface change)
What is the Koebner phenomenon?
Refers to skin lesions appearing on lines of trauma, e.g. psoriasis appearing at biopsy site or area of sunburn
What is the Auspitz sign?
the appearance of punctate (pinpoint) bleeding spots when psoriasis scales are scraped off
What is the id reaction?
In an id reaction, ERYTHEMATOUS VESICLES usually are seen on the lateral aspects of the fingers and the palms and are typically PRURITIC. This eruption of vesicles is usually sudden and classically occurs in response to an intense inflammatory process, especially FUNGAL infections (e.g. tinea pedis), taking place SOMEWHERE ELSE on the body. Treatment of the underlying infection results in resolution.
What is the Nikolsky sign?
A clinical dermatological sign, when slight rubbing of the skin results in exfoliation of the outermost layer, forming a blister within minutes.
Nikolsky’s sign is almost always present in toxic epidermal necrolysis (TEN) and is associated with pemphigus vulgaris. It is useful in differentiating between pemphigus vulgaris (where it is present) and bullous pemphigoid (where it is absent).
Describe the system for classifying skin phototypes.
I - white, very fair, red or blond, blue eyes, freckles
always burns, never tans
II - white, fair, red or blond, blue, hazel, or green eyes
usually burns, tans with difficulty
III - cream white, fair with any eye or hair color, very common
sometimes mild burn, gradually tan
IV - brown, typical Mediterranean caucasian skin
rarely burns, tans with ease
V - dark brown, mideastern skin types
very rarely burns, tans very easily
VI - black
never burns, tans very easily
Name and describe the three stages of hair growth.
Anagen - growth; 85% of hair, rapidly dividing
average 3 years
beard, scalp - long anagen
eyebrows, pubic - short anagen
Catagen - regression; apoptosis-driven, 3% of hair
3 weeks
Telogen - resting; 10-15% of hairs
about 3 months
extremities, eyebrow, pubic/axillary - long telogen
Differences between MSSA and MRSA cellulitis
Drugs to treat each
MRSA is a more effective colonizer; has higher rates of adverse outcomes and treatment failure; has higher cost of care
MRSA: Clindamycin, TMP-SMZ, Vancomycin
MSSA: Cephalexin, dicloxacillin
Name the organism(s) associated with impetigo
S. aureus, GAS
Name the organism(s) associated with erysipelas
GAS
Name the organism(s) associated with cellulitis
S. aureus, GAS
Name the organism(s) associated with erythrasma
Corynebacterium minutissimum
Name the organism(s) associated with necrotizing fasciitis
GAS, S. aureus, Clostridium, polybacterial
Name the organism(s) associated with pitted keratolysis
Kytococcus sedentarius
Name the organism(s) associated with tinea capitis, barbae, corporis, unguium, cruris, pedis
tinea pedis: Trichophyton rubrum
tinea capitis: Trichophyton tonsurans
tinea corporis: T. rubrum; M. canis
tinea cruris: T. rubrum; T. mentagrophytes
tinea barbae: T. verrucosum; T. mentagrophytes
tinea unguium: T. rubrum; T. mentagrophytes
Name the organism(s) associated with tinea versicolor
Malassezia (tinea versicolor is not a true tinea….more accurate name is pityriasis versicolor)
Name the organism(s) associated with candidiasis
yeast, C. albicans
Name the organism(s) associated with molluscum contagiosum
poxvirus
Name the organism(s) associated with verrucae
HPV
KOH - method and findings
scraping + slide + drop of KOH + microscope
looking for fungal hyphae; “spaghetti & meatballs”
diascopy - purpose and technique
to check for blanching: clear slide + press against lesion and observe through slide
viral culture - key points
- Take a sample by rubbing a sterile swab on the lesion
· Must include cells not just fluid from the blister
· Optimal if removed during the acute (worse) phase
· highly dependent on appropriate selection, collection, and handling of biological specimens.
· When delays are expected, viral samples should be refrigerated at 4⁰C
fungal culture - key points
May be done after a KOH prep
Results may take weeks
Limited application
Samples easily contaminated by bacteria
acetowhitening
- -purpose
- -indications
- -collection procedure
- -clinical use
Purpose: to identify areas of squamous cell change
Indications: abnormal Pap or HPV test; abnormal cervix appearance; abnormal bleeding
Collection procedure: during colposcopy, apply acetic acid solution to cervical area of concern; biopsy areas of whitened cells (abnormal) and study histologically
Clinical use: diagnose cervical dysplasia, HPV
Gram stain
- -purpose
- -procedure
- -interpretation
Purpose: to differentiate between Gram-negative and Gram-positive bacteria; to visualize morphological bacterial features
Procedure:
- specimen on slide
- apply crystal violet, rinse
- apply iodine, rinse
- apply decolorant, rinse
- apply counterstain (safranin red), rinse
Interpretation: Gram-positive = dark purple or blue, Gram-negative = pink/red
Wood's light What are the clinical interpretations of interest? Erythrasma Pseudomonas Tinea capitis Tinea versicolor Pigmented lesions of the epidermis Pigmented lesions of the dermis Vitiligo False positives
Erythrasma: coral pink
Pseudomonas: green
Tinea capitis: T. tonsurans does not fluoresce; Microsporum fluoresces bright green
Tinea versicolor: orange-yellow
Pigmented lesions of the epidermis: accentuated
Pigmented lesions of the dermis: faded
Vitiligo: white
False positives: scale, soap, fibers, ointments, scars
bacterial (wound) culture
Specimen must contain:
What are the indicative factors about the growth conditions in the lab?
Specimen must contain exudate and/or necrotic tissue!
Much can be learned from the medium on which growth takes place/doesn’t occur, as well as the oxygen availability
herpes serology
Purpose
Indications
Purpose: Designed to detect an antibody response in serum samples after an exposure; To distinguish between two serotypes; HSV 1 (oral) and HSV 2 (genital); to enable targeted treatment with appropriate antivirals
Indications: PE findings e.g. vesicles, pustules, shallow ulcers with erythematous base; recent exposure; pregnant women
Tzanck smear
Purpose
Technique
Findings
A Tzanck smear is a cytologic technique most often used in the diagnosis of herpesvirus infections (HSV or VZV). An early vesicle, not a pustule or crusted lesion, is unroofed, and the base of the lesion is scraped gently with a scalpel blade. The material is placed on a glass slide, air-dried, and stained with Giemsa or Wright’s stain. MULTINUCLEATED EPITHELIAL GIANT CELLS suggest the presence of HSV or VZV; culture or immunofluorescence, or genetic testing must be performed to identify the specific virus.
melanoma main risk factors? what is the number one indicator of prognosis? what is the ugly duckling sign? what are 3 factors of assessment? What is the ABCDE assessment?
Main risk factors: UVR; > 100 nevi; skin phototype I or II
The number one indicator of prognosis is thickness of lesion/tumor. Thicker is bad.
Ugly duckling sign: one mole stands out as different-looking amongst a field of moles
3 assessments: dermoscopy by an experienced clinician; excision with NARROW margins (to preserve tissue for later excisional surgery); histological assessment by an experienced dermatopathologist
ABCDE: Asymmetry Border Color Diameter Elevation/Evolving
Mohs micrographic surgery
- What are the benefits?
- What kind of cancer is it the most effective in curing?
- What other cancers is it used for?
- High cure rate with lowest cosmetic issues
- Highest cure rates for BCC; slightly less with SCC
- May be used for some melanoma as well
What is the difference between eczema and dermatitis?
The terms eczema and dermatitis are used interchangeably, denoting a polymorphic inflammatory reaction pattern involving the epidermis and dermis. There are many etiologies and a wide range of clinical findings. Acute eczema/dermatitis is characterized by pruritus, erythema, and vesiculation; chronic eczema/dermatitis, by pruritus, xerosis, lichenification, hyperkeratosis, ± fissuring.
Name 6 general treatments for psoriasis.
- emollients/keratolytics
- corticosteroids
- coal tar
- phototherapy
- methotrexate
- cyclosporine
Name 5 adverse side effects of topical steroids.
- HPA suppression
- dermatitis
- hypopigmentation
- skin atrophy
- striae
Describe asteatotic dermatitis
A common pruritic dermatitis that occurs especially in OLDER persons, in the winter in temperate climates—related to the low humidity of heated houses.
—The sites of predilection are the legs, arms, and hands but also the trunk.
—Dry, “cracked,” superficially fissured skin with slight scaling.
—The incessant pruritus can lead to LICHENIFICATION, which can even persist when the environmental conditions have been corrected.
—The disorder results from too frequent bathing in hot soapy baths or showers and/or in older persons living in rooms with a high environmental temperature and low relative humidity.
What condition is described as “dew drops on a rose petal” presentation?
Herpes simplex (grouped vesicles on an erythematous base)
What do you think if you hear “rodent ulceration”?
Basal cell carcinoma
What do you think if you hear “umbilicated”?
molluscum contagiosum
What is a classic diagnostic sign for warts?
black dots (thrombosed capillaries)
What is a side effect risk of cryotherapy (e.g. liquid nitrogen)?
hypopigmentation, hyperpigmentation
What are three treatments for warts?
freezing, salicylic acid, duct tape
If you see comedones you know it’s _____
acne
What are the TOPICAL treatments for acne?
benzoyl peroxide
retinoids
topical ABX
keratolytics/salicylic acid
What are the SYSTEMIC treatments for acne?
oral antibiotics (doxycycline, minocycline)
isotretinoin
intralesional steroids
OCPs
Differences between acne vulgaris and rosacea:
distribution
comedones
acne vulgaris: face/trunk
rosacea: cheeks/chin, forehead/nose
comedones: MUST have for acne vulgaris; do NOT have in rosacea
How much mass is a fingertip unit?
1 FTU = 0.5 g
Which is least drying? Which is most drying? powder cream lotion tincture gel ointment
LEAST DRYING (best for conditions like eczema): OINTMENT
CREAM is the next most emollient/least drying
LOTION
GELs can be drying (depends on alcohol content)
TINCTURES are drying (the purpose of a tincture is to dry)
POWDER
Define ointment cream lotion gel tincture powder
ointment: homogeneous, greasy, semi-solid; no surfactant or detergent. E.g. Vaseline, triamcinolone
cream/lotion: These are emulsions with oils and water and include a surfactant so the two will mix together. They can contain preservatives, humectants and stabilizers as well (which can be irritants). They need to be rubbed in, and therefore can be drying. Cream is a more solid form, while a lotion is a more liquid form. The more liquid it is, the more drying it will be.
gel: Non-greasy mixtures of propylene glycol and water (can contain alcohol). They have a translucent appearance and are sticky.
Gels with alcohol are best for acute exudative lesions (poison ivy dermatitis)
Alcohol-free gels should be used for dry and scaling conditions.
tincture: plant or animal extract in alcohol
powder: powdered drug, or drug mixed with a delivery powder such as corn starch. Good for intertriginous areas to dry them (e.g. axilla, inguinal)
What is the MOA of topical corticosteroids? How is potency determined?
MOA: anti-inflammatory, inhibit cell division, cause vasoconstriction
Potency is determined by ability to vasoconstrict
What is the lowest potency topical corticosteroid?
What are the intermediate potency topical corticosteroids? (4)
What are the highest potency topical corticosteroids? (3)
What classes are the highest potency and the lowest potency?
lowest: hydrocortisone
intermediate: triamcinolone, fluocinolone, halcinonide, mometasone
highest: betamethasone, clobetasol, halobetasol
Class I is the highest potency; class VII is the lowest potency.
What is tachyphylaxis?
Defined as the decrease in drug response when used over a prolonged period of time, tachyphylaxis is commonly observed during corticosteroid topical therapy. It is now thought that decreased adherence may be a contributing factor, rather than loss of corticosteroid receptor function. Increase in adherence may be achieved by asking patients to use it only on weekends (weekend therapy) or specific days of the week (pulse therapy).
Name 5 factors that increase absorption of topical corticosteroids (or any topical drug).
- -Thin skin location e.g. eyelids
- -Wet skin
- -Occlusion (e.g. plastic wrap, but includes intertriginous areas)
- -Greasy ointment base
- -Rubbing it in
We already know that a fingertip unit is 0.5 g. How many grams of topical preparation are needed for a single application on: face scalp arm hand (both sides) one side of trunk one leg + foot anogenital area whole body
From Fitzpatrick table 214-1:
face: 1 g
scalp: 2 g
arm: 3 g
hand (both sides): 1 g
one side of trunk: 4 g
one leg + foot: 5 g
anogenital area: 1 g
whole body: 30 - 40 g
Or: 1 g for face, hand, anogenital area 2 g for scalp 3 g for arm 4 g for one side of trunk 5 g for one leg + foot 30-40 g for whole body
topical liquid nitrogen indications contraindications 3 techniques adverse effects
indications: skin neoplasms
contraindications: lesions that require histopathology! cold intolerance, cold urticaria, lesions with indistinct borders, darkly pigmented melanomas
3 techniques: open spray, closed, dipstick
adverse effects: nerve damage, scarring, hypopigmentation, pain, alopecia
Disorders for which to give highest potency topical corticosteroids: (5)
psoriasis lichen simplex chronic severe eczema severe poison oak/ivy alopecia areata
Disorders for which to give medium potency topical steroids: (5)
atopic dermatitis nummular eczema asteatotic eczema scabies (after scabicide) contact dermatitis
Disorders for which to give low potency topical steroids: (5)
diaper dermatitis facial dermatitis anal dermatitis eyelid dermatitis intertrigo
If you see peau d’orange, what do you think of?
erysipelas
Describe the staging of decubitus ulcers.
Stage I: nonblanchable erythema of intact skin
Stage II: partial thickness skin loss involving epidermis and may include dermis
Stage III: Full-thickness skin loss involving damage or necrosis of subcutaneous tissue that may extend to, but not through, underlying fascia
Stage IV: Full-thickness skin loss with extensive necrosis of or damage to muscle, bone, or supporting structures
What do you think if you see pruritic, clear, “tapioca-like” vesicles along finger edges?
Dyshidrotic eczema
Name 2 disorders you may use Burrow’s solution/dressing on.
Dyshidrotic eczema, contact dermatitis
What is the allergic triad associated with atopic dermatitis?
asthma, eczema, allergic rhinitis
Lichenification is a characteristic feature of _____
atopic dermatitis
Dyshidrotic eczema topical glucocorticoid treatment:
high potency with plastic occlusive dressing for 1-2 weeks
Describe nummular eczema and its treatments.
Well-demarcated coin-shaped plaques. Chronic plaques are dry, scaly, and lichenified. Topical steroids in the mid- to high-potency range are the mainstay of treatment. The calcineurin inhibitors, tacrolimus and pimecrolimus, and tar preparations are also effective.
What is xerosis?
dry skin
Solar lentigo
Circumscribed pigmented macules occurring singly or as multiple lesions and present on the skin surface exposed to UVR. Also known as sun-induced freckles, liver spots, senile lentigo.
Miliaria
Miliaria results from disruption of sweat ductal integrity with consequent sweat secretion into layers of the epidermis. Ultraviolet light exposure, resident organisms on skin, and repeated sweating episodes are facilitating factors. Focal anhidrosis can occur and persist for several weeks, much longer than the miliaria in affected skin regions.
Dermatoheliosis
photoaging
Persons with skin phototype I and II are most susceptible.
The skin is waxy, deeply wrinkled, and dry.
Higher risk of skin cancer is indicated.
Polymorphous light eruption
Polymorphous light eruption is a term that describes a group of heterogeneous, idiopathic, acquired, acute recurrent eruptions characterized by DELAYED (within hours; lasts for 7-10 days) abnormal reactions to UVR.
Pruritis and paresthesias.
Porphyrias (hetergeneous group of heme metabolism disorders)
Metabolic Photosensitivity
Chemical induced or genetic
Adult onset
- “Fragile Skin” from painful erosions
- Tense bullae on hands and feet based on sun exposure
- Gradual onset
- Urine sample: red/pink fluorescence of urine
Folliculitis
most common organisms
treatment
variants
A pustule at a follicular opening represents folliculitis. Deeper follicular infections are called furuncles (single follicle) and carbuncles (multiple follicles). Staphylococci and streptococci are the most frequent pathogens.
Treatment consists of measures to remove follicular obstruction—either cool, wet compresses for 24 hours or keratolytics such as those used for acne. Topical or oral anti-staphylococcal antibiotics may be required.
pseudomonas folliculitis
Also known as “hot tub” folliculitis; arises hours to days after bathing in inadequately disinfected warm water. Result is eruption of scattered small red itchy or tender bumps, some may be pustular. Bacteria often associated with is Pseudomonas aeruginosa. Tx: Mild cases resolve on their own; severe can be treated with systemic antibiotics against gram negative bacteria
Pseudofolliculitis barbae
“Shaving bumps” or “razor rash”; a type of folliculitis; a foreign-body inflammatory reaction surrounding ingrown facial hair which results from shaving. Occurs more commonly in people with curly hair. Tx: let beard grow for 30 days to eliminate ingrown hairs. Use moisturizing shaving foam. Use a single blade razor when shaving resumed (double blade razor cut hairs too short, allowing them to grow in). Alternatively use electric shaver. Rx: Tetracycline or similar.
Beau’s lines are associated with ____
Pitted nails are associated with ____
telogen effluvium
psoriasis
4 differences between bullous pemphigoid and pemphigus vulgaris
- bullous pemphigoid is pruritic; p.v. is not
- bullous pemphigoid the bullae will be present; p.v. the bullae have all broken open and will not be present anymore
- bullous pemphigoid is not usually fatal; p.v. is serious and can be deadly
- bullous pemphigod = negative Nikolsky sign; p.v. = positive Nikolsky sign
Hidradentitis suppurativa
A chronic, suppurative, often cicatricial disease of APOCRINE gland–bearing skin.
Involves the axillae, the anogenital region.
May be associated with severe nodulocystic acne and pilonidal sinuses (termed follicular occlusion syndrome).
MANY BLACK COMEDONES, some of which are paired, are a characteristic finding, associated with deep, exquisitely painful abscesses and old scars.
Rosacea appearance distribution how to differentiate from acne vulgaris treatment
INCREASED CAPILLARY ACTIVITY
Persistent erythema, telangiectases, papules, pustules; rhinophyma
Commonly distributed symmetrically on the face (cheeks, chin, forehead, glabella and nose)
NO COMEDONES
tetracyclines
Name 2 treatments for hyperhidrosis.
- Mild cases of axillary and palmar sweating are controlled via topical application of aluminum chloride.
- Iontophoresis
Perioral dermatitis is strongly associated with ____.
Appearance:
Treatment:
Misuse/overuse of topical corticosteroids!
The primary lesions of perioral dermatitis are discrete and grouped erythematous papules, vesicles, and pustules. The lesions are often symmetric but may be unilateral and appear in the perioral, perinasal, and/or periocular regions.
If topical corticosteroids are being used, they should be discontinued. In most cases, effective therapy is oral tetracycline, doxycycline, or minocycline.
Acne vulgaris treatments for mild, moderate, and severe:
Mild acne:
Topical antibiotics (clindamycin and erythromycin)
Benzoyl peroxide gels
Topical retinoids
Moderate acne:
Oral antibiotics are added to the above regimen, intralesional triamcinolone
Severe acne:
Systemic treatment with isotretinoin
What is acne conglobata?
Severe cystic acne with more involvement of the trunk than the face. Coalescing nodules, cysts, abscesses, and ulceration; occurs also on buttocks.
Renal transplant is associated with:
sebaceous hyperplasia
10-15% of people using cyclosporine develop:
sebaceous hyperplasia
What does sebaceous hyperplasia look like in newborns? In older people?
Newborns: Prominent white to yellow papules at the opening of pilosebaceous follicles without surrounding erythema—especially over the nose
Older adults: lesions are 1 to 3 mm in diameter and have both telangiectasia and central umbilication
Stasis dermatitis is a finding of chronic ____ disease
venous
What does stasis dermatitis look like?
Where does it typically occur?
It is characterized by erythema, scaling, pruritus, erosions, oozing, crusting, and occasional vesicles may occur during any stage of chronic venous insufficiency. Over time, lesions may lichenify.
It typically occurs in the medial supramalleolar region where microangiopathy is most intense.
Describe the appearance of thrombocytopenic purpura.
Who gets it?
Thrombocytopenic purpura is characterized by cutaneous hemorrhages occurring in association with a reduced platelet count.
Hemorrhages are usually small (petechiae) but at times larger (ecchymoses).
Occur at sites of minor trauma/pressure (platelet count < 40,000/L) or spontaneously (platelet count < 10,000/L)
Acute idiopathic thrombocytopenic purpura mostly in children; drug-induced and autoimmune TP in adults.
What is livedo reticularis?
purple lace-like pattern on lower extremities, sometimes seen in vasculitis
If you see a herald patch and a christmas tree distribution, what is it?
Pityriasis rosea
Pityriasis rosea What causes it? Who usually gets it? What does it look like? Treatment?
viral etiology (a herpesvirus?)
Most commonly affects young adults
Asymptomatic, Oval brown-colored plaques up to 2 cm in diameter sometimes accompanied with mild itching
Self-resolving
Seborrheic dermatitis
appearance
treatment
“Greasy scale”. Dry scales with underlying erythema is found on scalp, face ( in a T distribution across the forehead and down the nasal bridge), chest, back, umbilicus, eyelids and body folds
Shampoos with zinc or selenium are used for scalp seborrhea. Tar shampoos can also be used of milder cases. Low-potency corticosteroid creams are applied in non-scalp areas and topical steroid-sparing alternatives are offered (protopic and elidel).
What are the 4 P’s of lichen planus?
Treatment?
Typical age of onset?
Purple, pruritic, polygonal, papules
Treat with high potency topical steroids
Age 30-60
Can Koebnerize
Icthyosis
Describe
Causes? Age of onset?
Treatment?
describes a group of hereditary disorders characterized by an excess accumulation of cutaneous scale, varying from very mild and asymptomatic to life threatening.
Usually genetic, so starts at birth
Hydration and lubrication of the skin
Dermatofibroma appearance cause Telltale sign Treatment
3-10mm in diameter, domed but sometimes depressed.
Surface dull, shiny or scaly. Firm
Color: skin-colored, pink, brown, or dark chocolate brown.
Borders ill-defined.
Rarely tender.
Usually a reaction to an arthropod bite.
Dimple sign: squeeze on either side and the dermatofibroma inverts/becomes concave
Benign; no treatment necessary
Seborrheic keratoses
appearance
treatment
Early: 1-3mm barely elevated papule, later a larger plaque.
With or without pigment.
Surface has greasy feel and a hand lens shows FINE STIPPLING (like a thimble)
Late: 1-6cm. Flat nodule
Brown, gray, black, skin-colored. Round or oval.
Plaque w/ warty surface and “stuck on” appearance. Greasy.
Hand lens shows HORN CYSTS – always seen with dermoscopy.
Curettage after slight freezing with cryospray allows histology
Pyogenic granuloma
Rapidly developing vascular lesion usually following minor trauma that bleeds easily. Papule with a collar of hyperplastic epidermis at the base.
Keratoacanthoma Age of onset Causes Appearance & location 3 stages Treatment
Age of onset > 40 years. M:F ratio 2:1.
HPV have been identified in KAs
UV Radiation and chemical carcinogens (pitch, tar)
Variant of squamous cell carcinoma, rapidly growing epithelial tumor. Usually spontaneous regression after 6-12 months w/ scarring.
No symptoms, but occasional tenderness and cosmetic disfigurement.
- sun exposed sites, usually solo but multiple can occur.
3 stages
1) Dome-shaped nodule with central keratotic plug. Firm but not hard. Skin-colored, slightly red, brown. Removal of keratotic plaque results in a crater.
2) Hyperkeratosis replaces most of nodule, thin peripheral tumor tissue.
3) Hyperkeratosis and keratinization replace entire tumor
Tx by excision in early stages because SCC & KA indistinguishable by clinical findings.
Multiple KAs: Systemic retinoids and methotrexate
actinic keratosis causes signs & symptoms treatment strongest predictor of \_\_\_\_
Actinic Keratoses develop in response to prolonged exposure to UVR.
AK’s are small (0.2–0.6 cm) macules or papules—flesh-colored, pink, or slightly hyperpigmented—that feel like sandpaper and are tender when the finger is drawn over them
Physical Exam Findings- AK’s are found on sun-exposed areas of the body such as the face, dorsum of hand, neck, forearms.
Treatment methods include cryotherapy, curettage with or without electrosurgery, shave excision, topical agents, and photodynamic therapy
Strongest predictors of subsequent development of nonmelanoma skin cancer and melanoma!
dysplastic nevi
describe
Link to skin cancer?
Majority of lesions will involute and disappear over time. Normally found in 10% of the Caucasian population.
Signs & Symptoms- Moles are large and >6mm in diameter. Ill-defined, irregular border and irregularly distributed pigmentation. Normally flat or flat with a centrally elevated center.
Patients with 50 or more nevi with one or more atypical moles and one mole at least 8 mm or larger, and patients with few to many definitely atypical moles have an increased risk of melanoma.
What group of diseases is known for having a prodromal period? Describe the prodromal symptoms of the most painful & serious version of this group of diseases.
Herpesviruses often have prodromal periods.
Herpes zoster
Pain and paresthesia in the involved dermatome often precede the eruption by several days and vary from superficial itching, tingling, or burning to severe, deep, boring, or lancinating pain. The pain may be constant or intermittent and it is often accompanied by tenderness and hyperesthesia of the skin in the involved dermatome.
Exanthematous/morbilliform drug reaction
Fixed drug reaction
Describe each; drugs with high probability of reaction
Exanthematous drug reaction is a cutaneous eruption that mimics measles.
Usually quite pruritic, disturbs sleep
Drugs with high probability of this reaction: penicillin, sulfas, NSAIDs
A fixed drug eruption (FDE) is an adverse cutaneous reaction to an ingested drug, characterized by the formation of a solitary (but at times multiple) erythematous patch or plaque.
If the patient is rechallenged with the offending drug, the FDE occurs repeatedly at the IDENTICAL skin site (i.e., fixed) within hours of ingestion.
Some high probability drugs: Tetracyclines, sulfas, metronidazole, food coloring
Treatments for vitiligo
Want to repopulate melanocytes…
- UV therapy
- Corticosteroids
- Calcineurin inhibitor
- Psoralen (increases skin’s sensitivity to UVA - “PUVA” therapy - psoralen + UVA)
Cause of vitiligo
Vitiligo is a multifactorial, polygenic disorder, with a complex pathogenesis that is not yet well understood. Of various theories of disease pathogenesis, the most accepted is that genetic and nongenetic factors interact to influence melanocyte function and survival, eventually leading to AUTOIMMUNE DESTRUCTION OF MELANOCYTES.
Describe melasma
Macular hyperpigmentation of the face, the hue and intensity depending largely on the skin phototype of the patient. Light or dark brown or even black. Color is usually uniform but may be splotchy. Most often symmetric. Lesions have serrated, irregular, and geographic borders. Two-thirds on central part of the face: cheeks, forehead, nose, upper lip, and chin.
Treatments for melasma
hydroquinone (skin whitener!)
azelaic acid
What causes albinism?
What distinguishes albinism from other pigmentation disorders?
What is piebaldism?
Albinism is a recessive trait.
Ocular nystagmus and reduced visual acuity are important features of albinism that distinguish albinism from other congenital disorders of pigmentation.
In albinism there are melanocytes but they don’t function correctly. In other depigmentation disorders there is a lack of melanocytes.
Patients with piebaldism generally have depigmented patches on the ventral or lateral trunk and/or the mid-extremities, sparing the hands and feet. Poliosis (usually present as a white patch of hair) is a common feature.
For which skin phototypes is postinflammatory hyperpigmentation a problem?
Postinflammatory epidermal melanin hyperpigmentation is a major problem for patients with skin phototypes IV, V, and VI.
Describe postinflammatory hyperpigmentation. What can cause it? How long does it last? Treatment? Lesions?
This disfiguring pigmentation can develop with acne, psoriasis, lichen planus, atopic dermatitis, or contact dermatitis or after any type of trauma to the skin. It may persist for weeks to months but does respond to topical hydroquinone, which accelerates its disappearance. Lesions are characteristically limited to the site of the preceding inflammation and have indistinct, feathered borders.
What do you think if you see an erythematous, scaly, plaque in a butterfly pattern across the face?
Cause of this disease?
Lupus erythematosus - autoimmune
What is scleroderma?
What is the facies?
What other condition is almost always present?
What happens with the mouth?
Hardening of the skin and internal organs - autoimmune
Mask facies
Raynaud phenomenon
Microstomia
Behcet’s syndrome
Cause
Treatment
Describe
Behcet’s syndrome is a disease that involves inflammation of the blood vessels. Doctors aren’t sure what causes Behcet’s. There is no cure. Treatment focuses on reducing pain and preventing serious problems.
Painful punched out ulcers erupt in a cyclic fashion in the oral cavity and/or genital mucous membranes. Orodynophagia and oral ulcers may persist/recur weeks to months before other symptoms appear.
Blindness, CNS abnormalities, and thrombosis or rupture of large vessels are the most serious complications
Treatments for psoriasis
mild
moderate
severe
mild: topical emollients, glucocorticoides, vit D3
moderate: above + phototherapy
severe: above + systemic methotrexate, acitretin, cyclosporine
Treatments for atopic dermatitis
For cutaneous hydration: warm soaks, occlusive emollients
Tar - antipruritic, anti-inflammatory
Phototherapy
Systemic: cyclosporine, methotrexate
Describe the oral dosing for onychomycosis
drug
timing of dosing
Itraconazole
“pulse dosing” - 200 mg BID for 1 wk, then 3 weeks off; repeat once
What is permethrin used for?
5% cream - scabies; leave on for 8-12 hours
1% cream - lice; leave on for 8 hours then rinse
What is crotamiton used for?
10% cream/lotion - scabies; apply entire body
What is lindane used for?
shampoo or lotion - lice
may be used for scabies but concerns about toxicity limit it to a single application
What are allyamines used for?
Topical: tinea pedis, cruris, corporis, tinea versicolor, candidiasis.
Systemic: tinea pedis, cruris, corporis, onychomycosis
How can you differentiate between milia and closed comedones?
Milia probably won’t have redness
Which will blanch and which won’t?
petechiae
telangiectasia
petechiae: nonblanching
telangiectasia: blanch
Name 3 drugs used to treat scabies.
- permethrin
- crotamiton
- lindane
Name 2 drugs used to treat lice.
- permethrin
2. lindane
Name 3 drugs used to treat seborrheic dermatitis.
- selenium sulfide (topical)
- ketoconazole
- pyrithione zinc shampoo
Name 4 drugs used to treat dermatophyte infections.
- imidazoles - clotrimazole, miconazole, ketoconazole
- triazoles - fluconazole, itraconazole
- allyamines - terbinafine
- griseofulvin
What are the differences between cellulitis and erysipelas?
Erysipelas: face; RAISED; well-demarcated; peau d’orange
Cellulitis: legs; not raised; poorly demarcated
What is cantharidin used to treat?
Molluscum contagiosum; verrucae
What is the difference in the distribution of irritant contact dermatitis and allergic contact dermatitis?
Irrititant contact dermatitis: stays limited to where the irritant contact occurred
Allergic contact dermatitis: may spread beyond where the irritant contact occurred
What distinguishes dyshidrotic eczema from plain old atopic dermatitis?
Dyshidrotic eczema is a VESICULAR eczema of the fingers, hands, and toes.
What skin condition is pre-cancerous (pre-SCC)?
Actinic keratosis
What skin condition is indistinguishable visually from SCC and must be biopsied to differentiate?
keratoacanthoma
