A condition that usually begins in childhood, alopecia areata affects the hair follicles and usually causes hair to fall out in small, round patches. This condition affects both men and women of all ages and ethnic backgrounds. In the United States, it is estimated that alopecia areata has affected four million people. While there is no cure for this condition, doctors may prescribe medications that are approved for other diseases to help hair grow back.
What Is Alopecia Areata?Alopecia areata is a disease that affects the hair follicles. It usually causes hair to fall out in small, round patches about the size of a quarter. Although many people with alopecia areata will have only a few bare patches, some people may lose more hair. In rare cases, alopecia areata can cause complete loss of hair on the head (alopecia areata totalis) or complete loss of hair on the head, face, and body (alopecia areata universalis).
Who Gets Alopecia Areata?In the United States, it is estimated that alopecia areata has affected four million people. It affects both men and women of all ages and ethnic backgrounds, and it usually begins in childhood. The disease tends to run in families. Approximately one in five people with alopecia areata will have a family member who is affected with alopecia areata.
What Causes It?Alopecia areata is an autoimmune disease. Normally, the immune system protects the body against infection and disease. However, in an autoimmune disease, your immune system mistakenly attacks a part of your own body. In alopecia areata, the immune system attacks the hair follicles.
Scientists do not know why the immune system attacks hair follicles in alopecia areata. However, scientists do believe that a person's genes may play a role in triggering the attack on the hair follicles.
(Click Alopecia Areata Causes for more information.)