Alopecia Areata
Alopecia areata is considered an autoimmune disease, in which the immune system, which is designed to protect the body from foreign invaders such as viruses and bacteria, mistakenly attacks the hair follicles, the tiny cup-shaped structures from which hairs grow.
Alopecia can lead to hair loss on the scalp and elsewhere. In most cases, hair falls out in small, round patches about the size of a quarter. In many cases, the disease does not extend beyond a few bare patches. Although uncommon, the disease can progress to cause total loss of hair on the head (referred to as alopecia areata totalis) or complete loss of hair on the head, face, and body (alopecia areata universalis). In alopecia areata, immune system cells called white blood cells attack the rapidly growing cells in the hair follicles that make the hair and the hair falls out. However, the follicle always has the potential to regrow hair, but it may also fall out again. No one can predict when it might regrow or fall out. The course of the disease varies from person to person. Some people lose just a few patches of hair, then the hair regrows, and the condition never recurs. Other people continue to lose and regrow hair for many years.
Alopecia areata is not a life-threatening disease. It does not cause any physical pain, and people with the condition are generally healthy otherwise. But for most people, a disease that unpredictably affects their appearance the way alopecia areata does is a serious matter. The effects of alopecia areata are primarily socially and emotionally disturbing. In alopecia universalis, however, loss of eyelashes and eyebrows and hair in the nose and ears can make the person more vulnerable to dust, germs, and foreign particles entering the eyes, nose, and ears. Alopecia areata affects people of both sexes and of all ages and ethnic backgrounds. It often begins in childhood.
Scientists do not know exactly why the hair follicles undergo these changes, however, if you have a close family member with the disease, your risk of developing it is slightly increased. If your family member lost his or her first patch of hair before age 30, the risk to other family members is greater. Overall, one in five people with the disease has a family member who has it as well, therefore, it is possible, but not likely, for alopecia areata to be inherited. Most children with alopecia areata do not have a parent with the disease, and the vast majority of parents with alopecia areata do not pass it along to their children.