Arab Board Dermatology Part 1 flashcards

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

Epidermal turnover time

Approximately 28 days from basal layer to stratum corneum shedding; accelerated in psoriasis to 3-5 days, producing parakeratosis and scale.

Langerhans cell marker

CD1a-positive epidermal antigen-presenting cell containing Birbeck granules; captures and presents antigen to T lymphocytes in skin immunity.

Direct immunofluorescence pemphigus

Intercellular IgG deposits in a net-like pattern throughout the epidermis, reflecting autoantibodies against desmoglein adhesion proteins.

Lupus band test

Granular IgG and C3 deposition along the basement membrane zone; positive in lesional skin of systemic lupus erythematosus.

Auspitz sign

Pinpoint bleeding after removal of scale in psoriasis, caused by thinning of the suprapapillary plate over dilated dermal capillaries.

Wickham striae

Fine white lacy lines on the surface of lichen planus papules, corresponding to hypergranulosis on histology.

Tzanck smear

Cytologic test of blister base showing multinucleated giant cells in herpesvirus infection or acantholytic cells in pemphigus.

Honey-colored crust

Classic feature of nonbullous impetigo caused by Staphylococcus aureus or Streptococcus pyogenes, typically in children.

Scabies burrow

Linear grayish track in web spaces and wrists containing the mite, eggs, and feces; confirms diagnosis with KOH microscopy.

Nikolsky sign

Separation of epidermis with lateral pressure; positive in pemphigus vulgaris and toxic epidermal necrolysis, negative in bullous pemphigoid.

Dermatitis herpetiformis deposits

Granular IgA at the dermal papillae on direct immunofluorescence; linked to gluten-sensitive enteropathy and treated with dapsone.

Gottron papules

Violaceous scaly papules over metacarpophalangeal and interphalangeal joints, characteristic of dermatomyositis.

Anti-dsDNA antibody

Highly specific marker for systemic lupus erythematosus; titers correlate with disease activity and nephritis risk.

Vitiligo associations

Autoimmune thyroid disease, pernicious anemia, Addison disease, and type 1 diabetes; depigmentation from melanocyte loss.

Exclamation-mark hairs

Short broken hairs tapering proximally at the edge of alopecia areata patches, indicating active disease.

Oil-drop sign

Yellow-red discoloration of the nail bed in psoriasis, caused by exudate and hyperkeratosis beneath the nail plate.

Ash-leaf macule

Hypopigmented polygonal macule in tuberous sclerosis, often the earliest skin finding and visible under Wood lamp.

Kawasaki diagnostic criteria

Fever over five days plus conjunctivitis, mucositis, rash, extremity changes, or cervical lymphadenopathy; risk of coronary aneurysms.

Incontinentia pigmenti

X-linked dominant genodermatosis lethal in males; four stages from vesicular to verrucous, hyperpigmented, and hypopigmented lesions.

Breslow thickness

Depth of melanoma invasion in millimeters from granular layer; strongest prognostic factor guiding sentinel node biopsy and margins.

Pautrier microabscess

Intraepidermal collection of atypical CD4+ T lymphocytes in mycosis fungoides, a cutaneous T-cell lymphoma.

Mohs micrographic surgery

Serial horizontal frozen-section excision achieving highest cure rates for basal and squamous cell carcinoma in high-risk sites.

Pulsed dye laser target

Oxyhemoglobin at 585-595 nm, used for port-wine stains, hemangiomas, and telangiectasias with minimal scarring.

Hyaluronidase reversal

Enzyme that degrades hyaluronic acid fillers, used to treat nodules or vascular occlusion after injection.

Nickel patch test

Nickel sulfate applied under occlusion for 48-72 hours; positive reaction indicates allergic contact dermatitis from metal.

Porphyria cutanea tarda

Blistering photosensitivity with urine fluorescing coral-red; associated with hepatitis C, alcohol, and hemochromatosis.

Polymorphous light eruption

Delayed pruritic papulovesicular eruption on sun-exposed skin hours after UV exposure, common in spring.

SCORTEN score

Prognostic tool for toxic epidermal necrolysis using age, heart rate, malignancy, BSA, urea, bicarbonate, and glucose.

DRESS syndrome

Drug reaction with eosinophilia and systemic symptoms occurring 2-8 weeks after drug start, with rash and organ involvement.

Isotretinoin monitoring

Teratogenic retinoid requiring pregnancy tests, contraception, and monitoring of lipids and liver enzymes during therapy.

Koebner phenomenon

Development of new lesions at sites of trauma, seen in psoriasis, lichen planus, vitiligo, and vitiligo-related disorders.

Filaggrin mutation

Loss-of-function variant impairing epidermal barrier and predisposing to atopic dermatitis, ichthyosis vulgaris, and allergic sensitization.