Alopecia is a general term for hair loss. Alopecia areata is a common cause of non-scarring (does not cause scarring to the scalp) hair loss that can occur at any age. It usually causes small, coin-sized, round patches of baldness on the scalp, although hair elsewhere such as the beard, eyebrows, eyelashes, body and limbs can be affected. In some people larger areas are affected and occasionally it can involve the whole scalp (alopecia totalis) or even the entire body and scalp (alopecia universalis).
It is not possible to predict how much hair will be lost. Regrowth of hair in typical alopecia areata is usual over a period of months or sometimes years, but cannot be guaranteed. The chances of the hair regrowing are better if less hair is lost at the beginning. Most people, with only a few small patches get full regrowth within a year. If more than half the hair is lost then the chances of a full recovery are not good. The hair sometimes regrows white, at least in the first instance. Most people get further attacks of alopecia areata. In alopecia totalis and alopecia universalis, the likelihood of total regrowth is less.
Causes of Alopecia Areata?
Hair is lost because it is affected by inflammation. The cause of this inflammation is unknown but it is thought that the immune system, the natural defence which normally protects the body from infections and other diseases, may attack the growing hair. Why this might happen is not fully understood, nor is it known why only localised areas are affected and why the hair usually regrows again.
Someone with alopecia areata is slightly more likely than a person without it to develop other autoimmune conditions such as thyroid disease, diabetes, lupus and vitiligo (white patches on the skin), although the risk of getting these disorders is still very low. If you have other symptoms then discuss these with your doctor. Your doctor may suggest a blood test.