What are the causes and symptoms of alopecia areata?

What are the causes and symptoms of alopecia areata?

Alopecia areata is an autoimmune disease, where a person's immune system attacks the body, in this case, the hair follicles. When this happens, the person's hair begins to fall out, often in clumps the size and shape of a quarter. The extent of the hair loss varies; in some cases, it is only in a few spots. In others, the hair loss can be greater. On rare occasions, the person loses all of the hair on his or her head (alopecia areata totalis) or entire body (alopecia areata universalis).

It is believed that the person's genetic makeup may trigger the autoimmune reaction of alopecia areata, along with a virus or a substance the person comes into contact with.

Alopecia areata is an unpredictable disease. In some people, hair grows back but falls out again later. In others, hair grows back and remains. Each case is unique. Even if someone loses all of his or her hair, there is a chance that it will grow back.