[Translated article] Trichoscopy in Alopecia Areata.

Alopecia areata is an autoimmune disease that affects the hair follicle and can present as bald patches on the scalp and hair loss in other parts of the body. Diagnosis is clinical but can be aided by trichoscopy, a simple, rapid technique that reduces the need for invasive procedures and can also help with monitoring treatment response. We review the usefulness of trichoscopy in alopecia areata. The most common trichoscopic findings are yellow dots, black dots, exclamation mark hairs, short vellus hairs, and coudability hairs. Other, less common, findings can also help establish a diagnosis. Good response to treatment is indicated by the disappearance of black dots, broken hairs, and exclamation mark hairs. The observation of yellow dots, by contrast, indicates chronic disease and poor response to treatment.