Recent evidence suggests that the mechanism of shedding of a telogen hair is an active process that may occur independent of the emerging anagen hair. Headington has described 5 functional subtypes of telogen effluvium, based on which portion of the hair cycle is abnormally shortened or lengthened. These subtypes represent variations on the principles discussed above. It is rarely possible to distinguish these subtypes clinically. A large percentage of adults have experienced an episode of telogen effluvium at some point in their lives.
Morbidity is limited to mild cosmetic changes.
No racial predilection exists. Because hormonal changes in the postpartum period are a common cause of telogen effluvium, women may have a greater tendency to experience this condition. Chronic telogen effluvium has been reported mainly in women. It is not uncommon for infants in the first months of life to experience an episode of telogen effluvium. The symptom of both acute and chronic telogen effluvium is increased hair shedding.