Approach to the adult female patient with diffuse nonscarring alopecia.

Alopecias are traditionally categorized by the presence or absence of scarring and by a diffuse or localized pattern. A common clinical conundrum is that of a woman presenting with the chief complaint of diffuse, nonscarring hair loss. We review the 4 main diagnostic possibilities for this clinical scenario: (1) female pattern hair loss (androgenetic alopecia), (2) acute and chronic telogen effluvium, (3) diffuse alopecia areata, and (4) loose anagen syndrome.