Alopecia areata is an autoimmune disease in which the body's own immune system mistakenly attacks the hair follicles from which hair grows. In most cases, the hair falls out in small, round patches about the size of a quarter. In rare cases, alopecia areata can cause more extensive hair loss on the head, face and body. The impact on a person's appearance can be a source of emotional stress.
Genetics may predispose some people to the disease. Alopecia areata affects people of all ages and ethnic backgrounds and often begins in childhood. The cause of alopecia areata is unknown, but a trigger, such as a virus or something in the environment, may cause the immune system to attack the hair follicles. The follicles shrink and hair production ceases. However, it's possible for the hair to regrow, as the stem cells that supply the follicle with new hair-growing cells do not seem to be targeted.
The course of alopecia areata is unpredictable and there is no known prevention. Small patches of hair loss usually regrow within one year. More extensive hair loss may take longer to regrow. Some people with alopecia areata have persistent hair loss, or have repeated episodes of hair loss. It is a good idea to keep hairless patches covered with sunscreen and sun-protective clothing (scarves, sunglasses, hats).
There is neither a cure for alopecia areata nor drugs approved for its treatment. However there are treatments that can help stimulate hair growth, though they don't prevent the appearance of new patches. Common treatments include:
- Corticosteroids (injections, oral, topical)
- Rogaine (minoxidil) applied topically
- Anthralin applied topically for 20-60 minutes ("short-contact therapy")
- Systemic immune-modulating agents, such as sulfasalazine