HEALTH: Alopecia areata
Alopecia is a condition that causes round patches of hair loss, and can lead to total hair loss.
Alopecia areata is a disorder characterized by loss of hair. Sometimes, this means simply a few bare patches on the scalp. In other cases, hair loss is more extensive.
Although the exact cause is not known, this is thought to be an autoimmune disorder in which the immune system, the body's own defense system, mistakenly attacks the hair follicles, the tiny structures from which hairs grow. Hair loss is the only noticeable symptom of this disorder. Hair loss is usually confined to the head and face, although the entire body may be involved.
Causes, incidence, and risk factors
The cause of alopecia areata is unknown. About a fifth of people with this condition have a family history of alopecia.
Alopecia areata is thought to be an autoimmune condition. This occurs when the immune system mistakenly attacks and destroys healthy body tissue.
Alopecia areata is seen in men, women, and children. A major life event such as an illness, pregnancy, or trauma occurs before the hair loss in some, but not most patients