Alopecia areata (al-oh-PEE-shah air-ee-AH-tah) is a highly unpredictable, autoimmune skin disease resulting in the loss of hair on the scalp and elsewhere on the body. This common but very challenging and capricious disease affects approximately 1.7 percent of the population overall, including more than 5 million people in the United States alone. Due to the fact that much of the public is still not familiar with alopecia areata, the disease can have a profound impact on one's life and functional status, both at work and at school.

In alopecia areata, the affected hair follicles are mistakenly attacked by a person's own immune system (white blood cells), resulting in the arrest of the hair growth stage. Alopecia areata usually starts with one or more small, round, smooth bald patches on the scalp and can progress to total scalp hair loss (alopecia totalis) or complete body hair loss (alopecia universalis).

Alopecia areata occurs in males and females of all ages and races; however, onset most often begins in childhood and can be psychologically devastating. Although not life-threatening, alopecia areata is most certainly life-altering, and its sudden onset, recurrent episodes, and unpredictable course have a profound psychological impact on the lives of those disrupted by this disease.