Anagen effluvium

Anagen effluvium is a generalized diffuse hair loss from follicles in the anagen growth phase with quite rapid development 1-4 weeks after the initial trigger. Hair loss can be quite extensive as it affects all follicles in an anagen stage of active growth and around 90% of the average person's hair follicles are at this stage at any one time. Anagen effluvium results from the simultaneous inhibition of cell division in hair follicles leading to a sudden stop in hair fiber production.

As with telogen effluvium, anagen effluvium can be caused by a wide range of triggers. Most significantly, some trigger factors may promote anagen effluvium and telogen effluvium, even within the same individual. This is a point worth noting when you read through the summary list of trigger factors for anagen effluvium below.

Anagen effluvium can be induced by poisoning with arsenic or thallium salts and other similar substances. Anagen effluvium may be observed as part of a larger medical hair loss condition such as alopecia areata. However, extensive anagen effluvium is most often seen in people undergoing chemotherapy as a cancer treatment. The whole point of cancer treatment is to slow down or stop rapidly dividing cells. This is good when trying to stop the development of tumors but hair follicles are also regions of very rapidly dividing cells. These cells produce the hair fiber and are some of the fastest dividing cells in the body that are not cancerous. Chemotherapy takes a shot gun approach by universally blocking rapid cell division regardless of whether the cells are actually cancerous or not.

Potential causes of anagen effluvium overview

There are many potential causes of anagen effluvium. More common causes are listed below and some are explained in greater detail elsewhere.

• Genetic hereditary disease - Pollitt's syndrome, Marie Unna type hypotrichosis
• Defective hormone production - Anagen effluvium may be associated with hypopituitarism (hypopituitary dwarfism, Simmond's disease, Sheehan's syndrome), thyroid gland defects (hypothyroidism, hyperthyroidism), Cushing's syndrome, and occasionally juvenile diabetes
• Nutrient deficiencies - Extreme deficiency of copper, iron, zinc, biotin, essential fatty acids, or vitamin C in the diet may lead to anagen effluvium
• Cancer treatments - Drug categories such as cytostatic drugs, alkylating drugs, and antimetabolic drugs cause anagen effluvium
• Ionizing radiation - X rays and gamma rays
• Toxic agents - Thallium, arsenic, lead, bismuth, vitamin A and derivative drugs