Anagen effluvium is the pathologic loss of anagen or growth-phase hairs. Classically, it is caused by radiation therapy to the head and systemic chemotherapy, especially with alkylating agents.: 753–4  Anagen effluvium is due to an acute injury to the hair follicles by an endogenous or exogenous cause, resulting in sudden diffuse shedding of structurally damaged hairs...