1. Background

• a normal hair cycles through a growing (anagen) phase lasting approximately 3 years followed by a resting (telogen) phase lasting about 3 months
• the hair is then shed and a new cycle begins with a new hair growing out of the follicle
• at any one time, 80-85% of hair follicles are in the growing phase and 15-20% are in the resting phase

2. Pathogenesis

• in Telogen Effluvium, a sudden stress causes the premature simultaneous transformation of a large number of hairs into the resting phase
• at the end of the 3 month resting phase, these resting hairs are simultaneously shed resulting in a diffuse hair loss
• the growing phase then begins and the scalp returns to normal after about 6 months
• stressful triggers include:
  • acute blood loss (i.e., blood donation)
  • childbirth
  • discontinuation of high dose corticosteroids or oral contraceptives
  • febrile illness
  • psychiatric stress
  • sudden, severe weight loss
• Telogen Effluvium may also be seen in infants during the first few months after birth

1. Cutaneous Manifestations

• sudden diffuse loss of large amounts of hair producing a marked thinning of the scalp hair
• occurs approximately 3 months after a stressful trigger
• hair loss is seen especially with brushing, combing, and washing of hair
• not associated with inflammation of the scalp or areas of alopecia (baldness)
• the hair follicles remain intact
• only rarely is more than 50% of the hair lost

1. Supportive

• reassurance that the scalp will return to normal within 6 months

1. Rudolph, A.M., Rudolph's Pediatrics. 19th Edition. p. 999 (1991).

2. Zitelli, B.J. and H.W. Davis, Atlas of Pediatric Physical Diagnosis. 3rd Edition. p. 258 (1997).