Alopecia areata is an autoimmune disorder that causes your hair to come out, often in clumps the size and shape of a quarter. The amount of hair loss is different in everyone. Some people lose it only in a few spots. Others lose a lot.
Alopecia areata: Alopecia is the medical term for baldness. Areata means patchy. This patchy baldness can develop anywhere on the body, including the scalp, beard area, eyebrows, eyelashes, armpits, inside your nose, or ears.
Alopecia totalis: The person loses all hair on the scalp, so the scalp is completely bald.
Alopecia universalis: The person loses all hair, leaving the entire body hairless. This is rare.
Alopecia areata is caused by an abnormality in the immune system that damages hair follicles. This particular abnormality leads to autoimmunity, a misguided immune system that tends to attack its own body. As a result, the immune system attacks particular tissues of the body. In alopecia areata, for unknown reasons, the body’s own immune system attacks the hair follicles and disrupts normal hair formation.