OMSB Dermatology (OED) flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Pemphigus vulgaris

Autoimmune blistering disease with IgG antibodies against desmoglein 3, causing suprabasal acantholysis; direct immunofluorescence shows intercellular IgG and C3 in the epidermis.

Bullous pemphigoid

Subepidermal blistering disease with linear IgG and C3 along the basement membrane zone; targets BP180 and BP230; tense blisters in elderly patients.

Dermatitis herpetiformis

Pruritic vesicular disease with granular IgA at dermal papillae tips; associated with celiac disease; treated with dapsone and gluten-free diet.

Auspitz sign

Pinpoint bleeding after removal of scale in psoriasis; reflects dilated capillaries in dermal papillae beneath a thinned suprapapillary plate.

Koebner phenomenon

Appearance of new lesions at sites of trauma or injury; classically seen in psoriasis, lichen planus, and vitiligo.

Wickham striae

Fine white reticular lines on the surface of lichen planus papules; correspond to hypergranulosis on histology.

Erythema multiforme

Targetoid lesions often triggered by HSV infection; Stevens-Johnson syndrome and TEN show mucosal involvement and epidermal detachment, with TEN exceeding 30% body surface area.

Lupus band test

Direct immunofluorescence of lesional skin showing granular IgG and C3 at the dermoepidermal junction; supports systemic lupus erythematosus.

Mohs micrographic surgery

Margin-controlled excision examining 100% of surgical margins; indicated for high-risk basal cell carcinoma, squamous cell carcinoma, and dermatofibrosarcoma protuberans.

Breslow thickness

Measured from the granular layer to the deepest melanoma cell; determines prognosis and surgical margins (1 cm for lesions <=1 mm).

Sentinel lymph node biopsy

Procedure to identify the first draining lymph node; considered for melanoma >1 mm Breslow thickness or thinner lesions with ulceration.

Punch biopsy

3-4 mm cylindrical biopsy preserving tissue architecture; preferred for inflammatory dermatoses; shave biopsy is inadequate for assessing depth.

Sclerotherapy

Injection of sclerosing agents such as sodium tetradecyl sulfate or polidocanol for telangiectasias; risks include hyperpigmentation and ulceration.

Cryotherapy

Liquid nitrogen freezing for warts, actinic keratosis, and seborrheic keratosis; freeze time and thaw cycles determine tissue destruction; risk of hypopigmentation.

Intralesional corticosteroids

Triamcinolone 2.5-10 mg/mL injected for keloids, hypertrophic scars, and alopecia areata; higher concentrations risk atrophy.

Pulsed dye laser

Laser targeting oxyhemoglobin for vascular lesions such as port-wine stains and telangiectasias; Q-switched lasers target pigment instead.

Spongiosis

Intercellular edema in the epidermis; hallmark of eczematous dermatitis such as atopic dermatitis and contact dermatitis.

Acantholysis

Loss of intercellular cohesion between keratinocytes; seen in pemphigus vulgaris, Hailey-Hailey disease, and Darier disease.

Interface dermatitis

Lymphocytic infiltrate obscuring the dermoepidermal junction; causes include lichen planus, lupus erythematosus, and erythema multiforme.

Pautrier microabscesses

Intraepidermal collections of atypical lymphocytes; characteristic of mycosis fungoides and other cutaneous T-cell lymphomas.

Dermatofibroma

Dermal spindle cell proliferation with collagen trapping at the periphery; positive for factor XIIIa and negative for CD34.

Horn pseudocysts

Keratin-filled cysts within seborrheic keratosis; histology shows basaloid cells without atypia; clinical 'stuck-on' appearance.

Congo red stain

Stain for amyloid; under polarized light shows apple-green birefringence; used in macular and lichen amyloidosis.

Leukocytoclastic vasculitis

Small vessel vasculitis with fibrinoid necrosis, nuclear dust, and extravasated erythrocytes; presents as palpable purpura.

Kawasaki disease

Fever >=5 days with conjunctivitis, oral mucositis, rash, extremity changes, and lymphadenopathy; risk of coronary aneurysms; treated with IVIG and aspirin.

Hemangioma of infancy

Vascular tumor proliferating in first months and involuting over years; oral propranolol is first-line for problematic lesions.

Molluscum contagiosum

Umbilicated papules caused by a poxvirus; often self-resolving; cantharidin or cryotherapy for persistent lesions.

Koplik spots

White lesions on the buccal mucosa preceding the measles rash; rash spreads cephalocaudally.

Tinea capitis

Scalp dermatophyte infection, commonly Trichophyton tonsurans in the US; requires oral griseofulvin or terbinafine; topical therapy alone is inadequate.

Diaper dermatitis

Irritant contact dermatitis most common; Candida superinfection shows satellite pustules; treat with barrier cream and topical antifungal if candidal.

Neonatal lupus

Annular erythematous plaques on face and scalp associated with maternal anti-Ro/SSA antibodies; usually resolves as maternal antibodies clear.

Topical calcineurin inhibitors

Tacrolimus and pimecrolimus are steroid-sparing agents for atopic dermatitis; avoid in children under 2 years per labeling.