Alopecia Areata (AA) causes hair loss in small, round patches that may go away on their own, or may last for many years. Some people with AA (about 5%) may lose all scalp hair (alopecia totalis) or all scalp and body hair (alopecia universalis). The immune system, for unknown reasons, attacks the hair root and causes hair loss.
AA usually begins with one or more small, round, coin-size, bare patches. It is most common on the scalp, but can involve any hair-bearing site including eyebrows, eyelashes, and beards. Hair may fall out and regrow with the possibility of full hair regrowth always present. AA usually has no associated symptoms, but there may be minor discomfort or itching prior to developing a new patch. Nails may have tiny pinpoint dents and may rarely become distorted.
AA is not contagious. It is an autoimmune disease in which the body’s immune system attacks itself, in this case, the hair follicles. The cause is not known. A person’s particular genetic makeup combined with other factors triggers AA.
It is likely the hair may regrow, but it may fall out again. The course of the disease varies from person to person, and no one can predict when the hair might regrow or fall out again. This unpredictability of AA, and the lack of control over it, makes this condition frustrating.