ABD Dermatology flashcards

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

Filaggrin

Protein that aggregates keratin filaments and supports the cornified envelope; loss-of-function mutations impair barrier function and predispose to atopic dermatitis and ichthyosis vulgaris.

Auspitz sign

Pinpoint bleeding after removal of scale in psoriasis, reflecting thinned suprapapillary epidermis over dilated dermal capillaries.

Nikolsky sign

Separation of epidermis with lateral pressure; positive in pemphigus vulgaris and toxic epidermal necrolysis, indicating loss of keratinocyte adhesion.

Koebner phenomenon

Development of new skin lesions along lines of trauma or scratching; classically seen in psoriasis, lichen planus, and vitiligo.

ABCDE melanoma criteria

Asymmetry, Border irregularity, Color variation, Diameter greater than 6 mm, and Evolving lesion; used to flag pigmented lesions for biopsy.

Patch testing

Epicutaneous test for type IV delayed hypersensitivity; allergens applied and read at 48 and 72-96 hours to identify allergic contact dermatitis.

Topical steroid potency

Ranked class I super-high to class VII low; thinner skin on face and intertriginous areas absorbs more drug and needs lower-potency agents.

Methotrexate dosing

For psoriasis, methotrexate is given once weekly with folic acid supplementation; monitoring includes CBC, liver enzymes, and renal function.

Isotretinoin pregnancy prevention

Because isotretinoin is teratogenic, two negative pregnancy tests are required before starting and monthly testing plus contraception during treatment.

Narrowband UVB

Phototherapy using 311-313 nm ultraviolet B; first-line for widespread psoriasis and vitiligo, with cumulative dose tracking to limit carcinogenic risk.

Dapsone and G6PD

Dapsone causes hemolysis in G6PD deficiency and can cause methemoglobinemia; G6PD testing is required before initiating therapy.

Biologic pretreatment screening

Before TNF-alpha, IL-17, or IL-23 inhibitors, screen for latent tuberculosis and hepatitis B to prevent reactivation during immunosuppression.

Acantholysis

Loss of intercellular adhesion between keratinocytes, producing rounded detached cells; seen in pemphigus vulgaris and Hailey-Hailey disease.

Spongiosis

Intercellular edema between keratinocytes that widens spaces and stretches desmosomes; hallmark of eczematous dermatitis on histology.

Lichenoid tissue reaction

Band-like lymphocytic infiltrate obscuring the dermoepidermal junction with basal vacuolar change and apoptotic keratinocytes (Civatte bodies).

Pautrier microabscess

Intraepidermal cluster of atypical lymphocytes seen in mycosis fungoides, reflecting epidermotropism of the malignant T-cell clone.

Peripheral palisading

Arrangement of basaloid tumor cells in parallel rows at nest edges with stromal clefting; characteristic histologic feature of basal cell carcinoma.

Tombstoning

Single row of basal keratinocytes remaining attached to the basement membrane after suprabasal acantholysis in pemphigus vulgaris.

Miliaria rubra

Pruritic erythematous papules from obstruction of eccrine ducts deeper in the epidermis; triggered by heat and occlusion in infants.

Erythema toxicum neonatorum

Benign neonatal eruption of eosinophil-rich pustules on an erythematous base appearing in the first days of life and resolving spontaneously.

Transient neonatal pustular melanosis

Pustules present at birth that rupture to leave collarettes of scale and hyperpigmented macules, most common in darkly pigmented newborns.

Infantile hemangioma

Vascular tumor that proliferates in early infancy then involutes; complicated lesions may be treated with oral propranolol.

Kawasaki disease criteria

Fever over 5 days plus conjunctivitis, mucosal changes, rash, extremity changes, and cervical lymphadenopathy; risk of coronary artery aneurysms.

Staphylococcal scalded skin

Superficial epidermal cleavage from exfoliative toxin with diffuse erythema and desquamation; treated with antibiotics and supportive care.

Piebaldism

Congenital leukoderma with a white forelock and ventral midline depigmented patches due to KIT gene mutations; distinct from vitiligo.

Gottron papules

Erythematous violaceous papules over knuckles and interphalangeal joints; characteristic cutaneous finding of dermatomyositis.

Heliotrope eruption

Violaceous erythema of the upper eyelids seen in dermatomyositis; often accompanies Gottron papules and photosensitive poikiloderma.

Discoid lupus erythematosus

Chronic scarring plaques with adherent scale, follicular plugging, and atrophy; associated with anti-Ro/SSA and risk of progression to systemic lupus.

Sweet syndrome

Tender erythematous plaques with fever and neutrophilia; histology shows dense neutrophilic dermal infiltrate without true vasculitis.

Morphea

Localized scleroderma with indurated plaques and a violaceous active border; no systemic organ involvement or Raynaud phenomenon.

DRESS syndrome

Drug reaction with eosinophilia and systemic symptoms: rash, eosinophilia, and organ involvement, often with herpesvirus reactivation; requires drug withdrawal.

Leukocytoclastic vasculitis

Small-vessel vasculitis with nuclear dust and fibrinoid necrosis; presents as palpable purpura and warrants direct immunofluorescence and systemic workup.