In simple words: Anagen effluvium is a type of hair loss where the actively growing hairs are shed. This often happens due to medications, especially chemotherapy, that interfere with hair growth.

Anagen effluvium is the loss of hair in the anagen or growth phase.This is often caused by medications that impair cell division, such as those used in chemotherapy. It leads to rapid hair loss, typically from the scalp, but can also affect other body hair.

Example 1: A patient undergoing chemotherapy for breast cancer experiences rapid hair loss from the scalp, eyebrows, and eyelashes. This is diagnosed as anagen effluvium., A patient with alopecia areata experiences diffuse hair loss, and during examination, exclamation point hairs, a characteristic of anagen effluvium, are noted. Further investigation reveals the patient unknowingly ingested a toxin., A patient receiving radiation therapy for a brain tumor develops localized hair loss in the area of radiation exposure. This localized hair loss is identified as anagen effluvium.

Documentation for anagen effluvium should include detailed history (including medication history, exposure to toxins, and family history of hair loss), physical exam findings (description of hair loss, presence of exclamation point hairs), and any relevant laboratory or imaging results. If associated with a medical condition, such as an autoimmune disorder or cancer treatment, it should be noted.