EBDVD flashcards

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

Auspitz sign

Pinpoint bleeding when the scale of a psoriatic plaque is gently removed, reflecting thinning of the suprapapillary epidermis over dilated dermal capillaries.

Wickham striae

Fine whitish lacy or reticulate lines on the surface of lichen planus lesions, best seen on mucosal surfaces and on dermoscopy, and a hallmark of the disease.

Herald patch

A single larger oval salmon-coloured scaly macule that precedes the generalised truncal eruption of pityriasis rosea by about one to two weeks.

Koebner phenomenon

Development of new lesions of a skin disease along a line of trauma or scratching, classically seen in psoriasis, lichen planus and vitiligo.

Chancre

A painless indurated ulcer with a clean base and raised borders at the inoculation site in primary syphilis, appearing about three weeks after exposure and healing spontaneously.

Jarisch-Herxheimer reaction

Fever, chills, myalgia and transient worsening of lesions within hours of starting treatment for syphilis, caused by release of treponemal antigens and managed supportively.

Scabies burrow

A fine wavy greyish thread one to ten millimetres long in the stratum corneum, most often in finger webs, wrists and genitalia, containing the mite and its eggs.

Tzanck smear

A rapid cytological test in which scrapings from a vesicle base are Giemsa-stained; multinucleated giant cells indicate herpes simplex or varicella-zoster infection.

Breslow thickness

The vertical depth of melanoma invasion measured in millimetres from the granular layer to the deepest tumour cell; it is the strongest survival predictor and guides excision margins.

Blue-white veil

An irregular structureless blue-white area on dermoscopy caused by melanin within the dermis, a feature associated with melanoma and some pigmented basal cell carcinomas.

Patch test reading times

Allergen patches are removed at 48 hours and readings taken at day 2 and day 4 or 96 hours, so that late positive reactions are not missed.

Mohs micrographic surgery

Staged excision in which all peripheral and deep margins are examined on frozen sections, allowing maximal tissue conservation for high-risk or cosmetically sensitive tumours.

Lidocaine maximum dose

Up to 4.5 mg/kg without adrenaline and 7 mg/kg with adrenaline; 1% solution contains 10 mg/mL, so a 70 kg adult may receive about 31 mL of plain 1%.

Melanoma excision margins

Recommended clinical margins are 5 mm for melanoma in situ, 1 cm for tumours up to 1 mm thick, and 2 cm for tumours thicker than 2 mm.

Infantile haemangioma

A benign vascular tumour appearing in the first weeks of life, proliferating for 3–6 months then involuting; it is GLUT-1 positive and oral propranolol is first line for problematic lesions.

Ash-leaf macule

A hypopigmented lanceolate leaf-shaped macule, often the earliest cutaneous sign of tuberous sclerosis and best visualised with a Wood's lamp in infants.

Nickel contact allergy

The most common contact allergen worldwide, producing delayed type IV reactions at sites of jewellery, watch straps and belt buckles, and confirmed by patch testing.

Adrenaline for anaphylaxis

Intramuscular adrenaline 0.5 mg (0.5 mL of 1:1000) into the anterolateral thigh in adults, or 0.01 mg/kg in children, repeated after five minutes if needed.

Lupus band test

Direct immunofluorescence of skin showing a continuous granular band of IgG and C3 at the dermo-epidermal junction, characteristic of lupus erythematosus.

Gottron papules

Violaceous scaly papules over the extensor surfaces of the metacarpophalangeal and interphalangeal joints, a pathognomonic cutaneous sign of dermatomyositis.

Anti-desmoglein 3 antibodies

Pathogenic IgG autoantibodies against desmoglein 3 that cause loss of adhesion in lower epidermis and mucosa, producing the flaccid blisters of pemphigus vulgaris.

Dermatitis herpetiformis

An intensely itchy vesicular eruption on extensor surfaces caused by granular IgA deposits in dermal papillae, associated with coeliac disease and treated with a gluten-free diet.

Fitzpatrick phototype

A six-point classification from I to VI based on burning and tanning response to sun exposure, used to estimate photodamage and skin cancer risk and to select laser settings.

Selective photothermolysis

The principle that a laser wavelength absorbed by a target chromophore, delivered in a pulse shorter than the target's thermal relaxation time, destroys the target with minimal surrounding damage.

Hyaluronidase

An enzyme that degrades hyaluronic acid fillers and is used to reverse over-correction, nodules or vascular occlusion, usually within hours of injection.

Sun protection factor

The ratio of the minimal erythema dose on sunscreen-protected skin to that on unprotected skin; it mainly reflects UVB protection and does not indicate UVA cover.

Duty of candour

A professional and statutory obligation to tell a patient promptly and openly when they have suffered harm or an error has occurred in their care, and to apologise.

Informed consent

A voluntary decision by a patient with capacity after receiving adequate information about the nature, risks, benefits and alternatives of a proposed intervention.

Methotrexate in psoriasis

A systemic agent dosed once weekly, typically 7.5–25 mg, with folic acid supplementation; it is teratogenic and requires contraception and regular blood monitoring.

Sentinel lymph node biopsy

Identification and removal of the first draining node using blue dye and radiolabelled colloid, used to stage melanomas thicker than 1 mm or with other high-risk features.

BRAF V600E mutation

An activating mutation found in roughly 40–50% of cutaneous melanomas, targeted by BRAF inhibitors such as vemurafenib, usually combined with a MEK inhibitor.

KOH microscopy

A bedside test in which 10–20% potassium hydroxide dissolves keratin so that fungal hyphae and spores, or scabies mites, can be seen under a light microscope.