Alopecia areata is a common and distressing disorder of unclear etiology, that is characterized by the sudden appearance of circular areas of total hair loss, leaving a smooth and nonscarred scalp. The number of bold patches is highly variable as is the course of the disease, which frequently shows spontaneous remission, but ocassionally may proceed to involve the entire scalp and/or body. Alopecia areata (AA) is a common disease of human beings that is characterized by an acute onset of focal, diffuse, or both forms of hair loss. The histological features comprisea dystrophic anagen or telogen follicle, that is usually accompanied by a mononuclear cellular infiltrate in and around hair follicles, but usually without scarring. "Alopecia" is a Latin term that means baldness, and "areata" refers to the patchy nature of the hair loss that is typically seen with this condition. The clinical presentation of the disease varies from small well-defined patches of hair loss to the diffuse involvement of the scalp (alopecia totalis) or the entire body (alopecia universalis). The majority of AA patients experience unpredictable episodes of relapsing and remitting. However, in many patients, it can be persistent, especially when the hair loss is extensive

Alopecia Areata