Alopecia areata is the sudden and complete loss of hair in coin shaped areas on a hair-bearing area of the skin, most commonly the scalp. It is most common in children but can appear at any age. It is felt to be evidence of autoimmunity but can also be influenced by stress.
Alopecia may be self-limited or can progress to extensive hair loss. The good news is the loss is not scarring and there are treatments to help stimulate hair regrowth.