Alopecia areata is a prevalent autoimmune skin disease resulting in the loss of hair on the scalp and elsewhere on the body. It usually starts with one or more small, round, smooth patches on the scalp and can progress to total scalp hair loss (alopecia totalis) or complete body hair loss (alopecia universalis). The scalp is the most commonly affected area, but the beard or any hair-bearing site can be affected alone or together with the scalp. Alopecia areata occurs in males and females of all ages, but onset often occurs in childhood. Over 6.6 million people in the United States and 147 million worldwide have, had or will develop alopecia areata at some point in their lives.
Alopecia areata is a highly unpredictable and cyclical condition. The affected hair follicles become very small and produce no visible hair above the skin’s surface. Hair can grow back in or fall out again at any time, and the disease course is different for each person. No matter how widespread the hair loss, most hair follicles remain alive and are ready to resume normal hair production whenever they receive the appropriate signal. In all cases, hair regrowth may occur even without treatment and even after many years.