OMSB Dermatology (OED) key terms

Pinpoint bleeding that appears when scale is gently removed from a psoriatic plaque, caused by elongation and thinning of suprapapillary epidermal plates over dilated dermal capillaries.

Appearance of new lesions of a skin disease along lines of trauma or injury in previously unaffected skin, classically seen in psoriasis, lichen planus, and vitiligo.

Chronic immune-mediated papulosquamous disease with sharply demarcated erythematous plaques bearing silvery scale, driven by IL-23/Th17 pathways and treated with topical agents, phototherapy, or biologics.

Pruritic inflammatory disorder producing violaceous, flat-topped polygonal papules with Wickham striae, often involving flexural skin, oral mucosa, nails, and genitalia.

Psoriasis Area and Severity Index; a composite score combining body-surface involvement and erythema, induration, and scale in four body regions, used to grade severity and monitor treatment response.

Intensely pruritic vesicular eruption on extensor surfaces with granular IgA deposits at the dermal papillae, representing the cutaneous manifestation of gluten-sensitive enteropathy.

Acute mucocutaneous reaction, usually triggered by herpes simplex, producing target lesions with three concentric zones and favoring acral skin; mucosal involvement may occur but is limited.

Severe drug-triggered epidermal necrolysis with detachment of less than 10 percent of body surface area plus mucosal erosions; overlaps with toxic epidermal necrolysis along a severity spectrum.

Life-threatening mucocutaneous reaction with epidermal detachment exceeding 30 percent of body surface area, most often drug-induced, managed in burn-type units with supportive care and immunomodulation.

Validated severity-of-illness score for toxic epidermal necrolysis using seven variables including age, heart rate, malignancy, body-surface detachment, urea, glucose, and bicarbonate to predict mortality.

Separation of the epidermis from the dermis when lateral pressure is applied to skin or blister roof, indicating loss of keratinocyte cohesion in pemphigus or epidermal necrolysis.

Autoimmune blistering disease with flaccid bullae and mucosal erosions caused by IgG against desmoglein 3, showing suprabasal acantholysis and intercellular IgG on immunofluorescence.

Autoimmune subepidermal blistering disease of older adults with tense pruritic bullae, caused by IgG against BP180 and BP230 hemidesmosomal antigens, showing linear IgG and C3 along the basement membrane.

Technique applying fluorochrome-labeled antibodies to the patient's own frozen tissue to detect in-vivo deposition of immunoglobulins or complement, essential for diagnosing autoimmune blistering diseases.

Technique in which perilesional skin is incubated in sodium chloride to cleave the basement membrane at the lamina lucida, localizing immune deposits to blister roof or floor.

Loss of cohesion between keratinocytes due to disruption of desmosomal attachments, producing rounded detached cells and clefts within the epidermis, characteristic of pemphigus and related disorders.

Abnormal, premature keratinization of individual keratinocytes, which appear eosinophilic with pyknotic nuclei, seen in actinic keratosis, squamous cell carcinoma in situ, and lichen planus.

Intercellular edema between keratinocytes that widens spaces and stretches desmosomes, producing a spongy appearance typical of eczematous dermatitis.

Band-like lymphocytic infiltrate obscuring the dermoepidermal junction with basal vacuolar change and keratinocyte apoptosis, seen in lichen planus and lichenoid drug eruptions.

Direct immunofluorescence finding of granular immunoglobulin and complement deposition along the dermoepidermal junction in lesional skin, supporting a diagnosis of cutaneous lupus erythematosus.

Noninvasive magnified examination of skin structures using polarized or nonpolarized light, improving diagnostic accuracy for pigmented lesions, inflammatory disorders, and infestations.

Clinical warning signs for melanoma: asymmetry, border irregularity, color variation, diameter greater than six millimeters, and evolving change over time.

Maximum depth of melanoma invasion measured in millimeters from the granular layer of the epidermis to the deepest tumor cell, the strongest predictor of prognosis and staging.

Malignant neoplasm of melanocytes with potential for metastasis, staged by tumor thickness, ulceration, mitotic rate, and nodal status; treated primarily by wide local excision with margin based on thickness.

Staging procedure identifying the first draining lymph node using radiotracer and dye, generally offered for melanomas thicker than 0.8 millimeters or with high-risk features.

Tissue-sparing technique excising skin cancer with complete margin examination of frozen sections by the surgeon, used for high-risk basal cell carcinoma, squamous cell carcinoma, and selected melanomas.

Most common skin cancer, arising from basal keratinocytes, typically a pearly papule with telangiectasia, locally destructive but rarely metastasizing; treated by excision, Mohs surgery, or topical therapy in selected cases.

Malignancy of keratinocytes often arising in sun-damaged skin or from actinic keratosis, with scaling, ulceration, and metastatic potential; treated by surgical excision with margin assessment.

Rough, erythematous keratotic macule or papule on chronically sun-exposed skin representing intraepidermal dysplasia, a precursor lesion of squamous cell carcinoma.

Chronic relapsing pruritic eczematous disease with impaired skin barrier and immune dysregulation, treated with emollients, topical corticosteroids, calcineurin inhibitors, and targeted systemic agents.

Classification of topical steroids into seven classes by vasoconstrictor assay, guiding selection by body site, disease severity, and patient age to balance efficacy against atrophy and systemic absorption.

Systemic antimetabolite used for psoriasis, eczematous disorders, and other inflammatory dermatoses; requires monitoring of blood counts, liver enzymes, and renal function, with folic acid supplementation.

Targeted protein drugs blocking specific cytokines or receptors, such as TNF-alpha, IL-17, IL-23, or IgE pathways, used for moderate-to-severe psoriasis, atopic dermatitis, and urticaria.

Acute febrile vasculitis of young children with conjunctivitis, oral changes, polymorphous rash, extremity changes, and cervical lymphadenopathy, risking coronary artery aneurysms; treated with intravenous immunoglobulin and aspirin.

Infantile hemangioma presenting as a bright red, raised vascular tumor that appears after birth, grows rapidly in infancy, then involutes; complicated lesions may require beta-blocker therapy.

Non-selective beta-blocker that is first-line systemic treatment for problematic infantile hemangiomas, reducing proliferation and accelerating involution under monitoring for bradycardia and hypoglycemia.

Heterogeneous group of inherited disorders with skin fragility and blistering after minor trauma, classified by the level of cleavage into simplex, junctional, dystrophic, and Kindler types.

Highly contagious paramyxovirus infection with fever, cough, coryza, conjunctivitis, Koplik spots, and a descending morbilliform rash; prevented by vaccination.

Infestation by Sarcoptes scabiei causing intense nocturnal pruritus with burrows, papules, and nodules, treated with topical permethrin or oral ivermectin plus treatment of contacts.