Common; 17/100 000 population

Sx:Sudden loss of hair in round or oval patches

Si:Nonscarring patchy hair loss; "exclamation mark" hairs; when regrows, may come in white ("hair turned white overnight")

Waxes and wanes

r/o other nonscarring alopecia: local active infection, drugs (chronic heparin, colchicine, methotrexate, bc pills, cyclophosphamide), xray rx, hypo- and hyperthyroidism, secondary syphilis (eyebrow and "moth-eaten" occipital hair), tinea capitis, TRICHOTILLOMANIA(nervous tic in which pt pulls own hair out). These contrast with scarring alopecia: trauma, lichen planus, tertiary syphilis, discoid lupus, postinfectious (deep mycosis, typical and atypical tuberculosis, pyoderma)

Lab:Screen for associated conditions w CBC, TSH/T₄ , FBS

Rx:

(Nejm 1999;341:964)

Steroids: topical clobetasol (Temovate) bid or intralesional triamcinolone.

Minoxidil topically as 2% ointment or lotion, or 5% solution, helps 85% within 6 wk (BMJ 1983;287:1015), may only prevent further loss and must be continued forever; adverse effects: minimal systemic absorption and its effects; cost: $2/d for 1 cc bid, OTC less costly

Anthralin (Drithro-creme) 0.1% × 2-4 h qd

if resistant, 5% minoxidil + 0.5% anthralin (Arch Derm 1990;126:756); or rarely topical immunotherapy like diphenylcyclopropenone (Derm Clinics 1996;14:739)