ABSTRACT
Anagen effluvium is a type of non-scarring alopecia with abrupt diffuse hair loss due to a direct action of an agent, which impairs or interrupts the metabolic or mitotic activity of the hair follicles in the anagen phase of hair cycle. Generally, anagen effluvium is reversible and hair regrowth is observed 2–3 months after cessation of the insult. Anagen effluvium affects equally men and women worldwide. Chemotherapy and the radiation on the head and neck are most commonly implicated in the induction of anagen effluvium. The differential diagnosis can be mainly included telogen effluvium, as well as trichotillomania, androgenetic alopecia, alopecia areata, and other causes of non-cicatricial alopecia. There are several tests which may help to confirm the diagnosis of anagen effluvium. The hair pull test is strongly positive and can suggest a diagnosis of anagen effluvium if more than 80% of hairs are released. Radiation for treatment of brain tumors may lead to diffuse anagen effluvium or cicatricial alopecia.
