You may have heard of telogen effluvium, in which emotional or physiological stress can cause the hair to rapidly thin or fall out completely, but you may not know be as familiar with the hair loss condition known as anagen effluvium.
Put simply, anagen effluvium is the rapid loss of anagen hair (hair follicles in the active growth phase) caused by cancer treatments such as systemic chemotherapy and radiation therapy (to the head).
This pathological hair loss is caused by the aggressive chemicals used to treat cancer, particularly treatments which use alkylating agents. The hair loss is often patchy at first, but becomes near total hair loss after numerous treatments. Many other drugs and medicines, often those used to treat common illnesses and diseases, can also cause anagen effluvium hair loss.
Hair regrowth
The good news for sufferers of anagen effluvium is that after the course of treatment is finished and chemicals are not introduced to the body any longer, the hair usually starts to grow back. It can take approximately six months for the first signs of hair regrowth to emerge, although this may of course vary from patient to patient.
Anagen effluvium is the pathologic loss of anagen hairs, classically caused by radiation therapy to the head and systemic chemotherapy, especially with alkylating agents.