Alopecia Areata is an autoimmune disease that causes hair loss in specific areas of the scalp or other parts of the body, such as eyebrows, eyelashes or beard. The immune system mistakenly attacks the hair follicles, which interrupts the hair growth cycle and causes hair shedding.
It manifests as completely smooth round or oval patches. In severe cases, it may progress to hair loss on the scalp (alopecia totalis) or all over the body (alopecia universalis).
There may be episodes of hair loss followed by partial or complete hair regrowth, although relapses are common.
Alopecia Areata can be hereditary and affects children and adults of any age, most commonly those under 20 years of age. Severe stress is a possible cause, but this is difficult to prove. It is not unusual for the condition to stop suddenly or even last for months or years.