Some patients with idiopathic diffuse hair loss present with chronic t
elogen effluvium. Most of these cases are women aged 30 to 60 years wh
o complain of severe hair shedding. Many describe unusually dense hair
prior to an abrupt onset of hair loss. The subsequent shedding fluctu
ates in severity and may persist for years. Distinctive clinical and h
istologic criteria for the diagnosis of chronic telogen effluvium are
described.