Clinical and Histological Challenge in the Differential Diagnosis of Diffuse Alopecia: Female Androgenetic Alopecia, Telogen Effluvium and Alopecia Areata – Part I

This document discusses the challenges in diagnosing female androgenetic alopecia (FAA), telogen effluvium (TE), and alopecia areata (AA). The authors suggest using clinical, dermoscopic, and histological differences to differentiate between the three disorders. They also recommend evaluating the menstrual cycle, checking for weight changes and drug therapy for TE, and looking for nail changes and association with other syndromes for diffuse AA. The light hair pull test is positive for both TE and diffuse AA, but microscopic evaluation of the hairs shed reveals dystrophic anagen hairs or "pencil point" hairs for diffuse AA, which easily rules out TE and FAA. Dermoscopy and scalp biopsy are useful tools in distinguishing between the three conditions.