Telogen effluvium.

Abstract

Kligman first coined the term telogen effluvium (TE) in 1961 to describe the state of increased shedding of otherwise normal telogen hairs. TE may be primary or secondary to a wide variety of potential triggers including febrile illness, drugs, thyroid disorders, and child birth. The diagnosis of secondary TE can be made by identifying known triggers from the history in the 3–4 months preceding the onset of increased hair shedding and by investigating to exclude endocrine, nutritional, or auto immune aetiologies. Scalp biopsy to identify the earliest stages of androgenetic alopecia may be required in some cases. Primary TE may be acute or chronic. In acute TE, the shedding resolves within 3–6 months and the hair density recovers completely. In chronic TE, the shedding can continue with minor fluctuations in severity for decades. In this review, possible causative factors, pathogenesis, clinical presentations and treatment options are discussed.