Alopecia areata is an autoimmune skin disease that results in the loss of hair on the body. The autoimmune process is characterized by the body’s own immune system attacking hair follicles. The three types of alopecia areata are:
Alopecia areata – skin loses hair in round sections of varying size
Alopecia areata totalis – complete loss of hair on the scalp alone
Alopecia areata universalis – loss of hair everywhere on the body
In alopecia totalis and alopecia universalis, total scalp hair loss is preceded by the appearance of a small number of round hairless patches on the scalp. Some people may experience itching associated with the loss of hair. Total hair loss of the scalp (alopecia totalis) usually takes about 6 months.
It is estimated that about 6.5 million people are affected by one of the three varieties of alopecia areata. Alopecia areata affects children more than adults; however, the disease can affect people of all ages and races.
Except in cases of extreme hair loss (alopecia universalis), hair often grows back in a matter of a few months with no medical intervention.