Psoriatic alopecia: acute and chronic hair loss in 47 patients with scalp psoriasis.

Symptomatic hair loss and alopecia were seen in psoriatic lesions of the scalp in 47 patients. Remarkably, in 66% of the cases it was an inaugural manifestation, and in 36% the scalp was exclusively involved. Therefore 34% of the patients presented with a primary manifestation of isolated scalp psoriasis. Hair loss varied in intensity from protracted to moderate and massive (36% in tufts). It presented as acute (51%), chronic (36%) or chronic recurrent (13%). Thirteen patients (28%) became aware of the hair loss with the beginning of therapy. The alopecia was found to be circumscribed in 75% of the cases and diffuse in 25%. In 2 cases psoriatic alopecia also manifested itself at sites other than the scalp. The telogen count was found to be increased up to 25-86% in the florid stage. Examinations under the light microscope showed a patchy perifollicular lymphohistiocytic infiltrate in the upper and middle dermis with adnexotropia in several cases. This infiltrate can alter the follicle epithelium and may lead to a granulomatous foreign-body reaction with destruction of the hair follicle. After topical antipsoriatic treatment, most of the reexamined patients showed complete hair regrowth, while 5 developed a residual scarring. Therefore, in the patient with circumscribed or diffuse symptomatic alopecia, with or without scarring, psoriatic alopecia should be considered.