Derm Flashcards
Malignant Melanoma
Irregular pigmented lesion >6mm in size. ABCDE. Most common site is back (M) and leg (F). Tumor thickness is prognostic. Hx of changing mole is number 1 reason for biopsy. Excision biopsy is Tx/diagnostic.
Atopic dermatitis
Rough, red plaques w/o, thickening (though it will toughen) or sharp margins of psoriasis. ++pruritis (more than seborrheic dermatitis).
Most common loc: Face, neck, upper trunk, elbows/knees
Typically begins in childhood.
Tx: Avoid irritants, reduce soap, use emolients (moisturizer) after shower, topical corticosteroids (strength depends on chronicity, location).
Lichen simplex chronicus
Chronic itching and scratching, most often on neck, ankles, wrist, perineum. Causes thickened excoriated skin with exaggerated skin lines.
Tx: high-potency topical corticosteroid
Psoriasis
Silvery scales on bright red, sharply demarcated plaques + nail pitting/onycholysis. Cause unknown- partially genetic. Worse in winter (vs summer).
NOT pruritic
Auspitz’s sign: removing scale causes pinpoint bleeds.
Tx: phototherapy for small plaques (
Pityriasis Rosea
Benign- many fawn-colored plaques + scaly eruptions following cleavage lines of trunk (xmas tree pattern). Often preceded by 2 weeks by large HERALD patch. Young>Old; F>M; spring+fall>other months.
Tx is symptomatic UVB, topical corticosteroids or oral antihistamines.
Seborrheic dermatitis
Dry scales w/ underlying erythema located on scalp, central face, presternal, interscapular folds, skin creases (NL folds), eyebrows, behind ears. Causes dandruff.
DOES NOT CAUSE PRURITIS
Tx: scalp: selenium sulfide or ketoconazole shampoo.
Face; topical ketoconazole or steroid if severe.
Creases: clotrimazole + steroid
How do you treat tinea? What is important to remember about tinea pedis?
Topical anti-fungals. If refractory or difficult to treat topically, Griseofulvin can be used. For tinea versicolor ketoconazole PO can be used (or fluconazole).
Interdigital tinea pedis is the most likely cause of cellulitis in the healthy
Actinic keratosis
Premalignant lesion related to sun exposure. Small (0.2-0.6 cm), pink, rough, TENDER, macule or papule. Rarely progresses.
Tx: biopsy to r/o SCC if lesion is indurated, tender, or bleeds spontaneously.
Intertrigo
Caused by macerating effect of heat, moisture, friction. Most likely in obese patient in humid climate. Body folds develop fissures, erythema, sodden epidermis. May be complicated by candidiasis.
Tx: hygiene, keep dry. Hydrocortisone plus imidazole(anti-fungal) or nystatin
Imitizole
class of topical anti-fungals.
Pompholyx; Vestibulobullous hand eczema
Small, clear vesicles stud skin at sides of fingers and on palms or soles (tapioca-like). Pruritis. Vesicles dry and area becomes scaly and fissured.
Appears in 3rd decade in pts with Hx of atopic background
Tx: Topical corticosteroids.
Impetigo
Superficial blisters filled with purulent material that rupture easily, w/ honey-colored crusts.
Etiology is staph or strep.
Tx: Soaks, scrubbing. Topical Abx (bacitracin, mupirocin) if small area, otherwise give systematic ABx (Cephalexin or Doxycycline). If MRSA is suspected, treat with Clindamycin, doxy, or TMP-SMZ.
Contact dermatitis
erythema and edema with pruritis followed by vesicles or bullae (allergic contact dermatitis). Later, weeping, crusting, or sec. infection.
Irritant is more common than allergic.
Tx: Acute, weeping: Wet dressings (30-60 mins several times/day); high-potency topical corticosteroid. Sub-acute- mid-potency corticosteroid. Chronic (lichenified)- high-super potency topical steroid .
Acne vulgaris: Comedonal
MOre mild form of acne made up of open and closed comedones.
Tx: Topical retionoid (tretinoin) is very effective. Wait 20 mins after washing to apply. Benzoyl peroxide and antibiotics if refractory.
Acne vulgaris: Papular or cystic Inflammatory acne
Tx depends on severity:
Mild: Benzoyl peroxide + topical erythromycin or clindamycin.
Moderate: Tetracycline or doxycycline or minocycline PO
(Erythromycin in preg)
Severe: Isotretinoin (oral retinoid- teratogenic) - make sure they have no bowel or bladder problems, depression.
Rosacea
A chronic erythema of face, forehead and cheeks, that SPARES PERIORBITAL area. Starts in middle age. Erythema and flushing, papules, pustules with Telangiectasia. Nose becomes bulbous.
Tx: Avoid EtOH, hot beverages, suck on ice cube. Topical metronidazole, oral tetracycline. Isotretinoin if refractory.
Folliculitis
Tx: Anhydrous ethyl EtOH containing aluminum chloride aplied 3-7x weekly for chronic, recurrant type.
**Pseudomonas folliculitis will clear spontaneously in healthy pts. All others treat with oral ABx based on susceptibility.
Miliaria
heat rash- on trunk and intertriginous areas. Hot moist environment is most frequent cause. Burning and itching with small, superficial, red, thin-walled disecrete vesicles, papules, or pustules.
Tx: tramcinolone acetide OR mid-potency corticosteroid.
Candidiasis Tx
Nails and paronychia- clotrimazole solution Skin- nystatin or clitrimazole cream Mucous membranes/vulva- Oral fluconazole Balanitis- topical nystatin Mastitis- Oral fluconazole
Urticaria & angioedema
Eruptions of wheals w/ intense itching- typically an IgE mediated immune reaction, insect bite. Can occur before blisters in contact dermatitis. Often caused by med allergies.
Tx: H1 antihistamines (hydroxyzine). In refractory, use 2nd gen antihistamines at 4x dose given for allergic rhinitis.
Erythema multiforme minor
Minor- most common cause is herpes- On extensor surfaces, palms, soles, mucous membranes.
Target lesions with clear centers and concentric erythematous rings.
Tx: Acyclovir if caused by herpes.
Erythema multiform major
See SJS and TEN
Stevens Johnson Syndrome and Toxic Epidermal Necrolysis
Erythema multiforme- drug induced. TEN is when >30% TBSA is involved.
Culprits are usually: sulfas, anticonvulsants, allopurinol, NSAIDs.
Purpuritic target-like lesions with two zones of colorg cange and a center blister, or nondescript red/purpuric macules.
Tx: Immediate cessation of offending med, nutritional and fluid support and high vigilence for infection. Burn unit if TEN. Manage lesions like 2nd degree burn.
Erysipelas
Superficial form of cellulitis that classically occurs on cheeks (bilat), caused by beta-hemolytic strep. Accompanied by pain, malaise, fever. Sharply-defined, raised border. Glistening, smooth, hot plaque. Dx- biopsy is diagnostic.
Tx: IV penicillin. If allergic or prefer PO- give 1st gen cephalosporin or clindamycin.
