Alopecia Areata is an autoimmune disease that causes hair to fall out in small, random patches. The hair loss usually affects the scalp, but it can also occur in other areas of the body.Alopecia areata is a disease that causes hair to fall out in small patches. It develops when the immune system attacks the hair follicles, resulting in hair loss. Sudden hair loss may occur on the scalp and other parts of the body. The condition rarely results in total hair loss, or alopecia universalis, but it can prevent hair from growing back. When hair does grow back, it’s possible for the hair to fall out again. The extent of hair loss and regrowth varies from person-to-person.
Alopecia Areata is "a common condition of undetermined etiology characterized by circumscribed, no scarring, usually asymmetric areas of baldness on the scalp, eyebrows, and bearded portion of the face."
The condition occurs when white blood cells attack the cells in hair follicles, causing them to shrink and dramatically slow down hair production. It is unknown precisely what causes the body's immune system to target hair follicles in this way.
Alopecia Areata is an autoimmune disease. An autoimmune disease develops when the immune system mistakes healthy cells for foreign substances. Normally, the immune system defends your body against foreign invaders, such as viruses and bacteria. If you have alopecia Areata, however, your immune system mistakenly attacks your hair follicles. Hair follicles are the structures from which hairs grow. The follicles become smaller and stop producing hair, leading to hair loss.
While scientists are unsure why these changes occur, it seems that genetics are involved as Alopecia Areata is more likely to occur in a person who has a close family member with the disease. One in five people with the disease has a family member who has also developed Alopecia Areata.
The main symptom of Alopecia Areata is hair loss. Hair usually falls out in small round patches on the scalp. These patches are usually several centimetres or less. Hair loss might also occur on other parts of the body. You may first notice clumps of hair on your pillow or in the shower. However, other types of diseases can also cause hair to fall out in a similar pattern. Hair loss alone shouldn’t be used to diagnose Alopecia Areata.
In rare cases, some people may experience more extensive hair loss. This is usually an indication of another type of alopecia, such as:
Alopecia totalis, which is the loss of all hair on the scalp
alopecia universalis, which is the loss of all hair on the entire body
The hair loss associated with Alopecia Areata is unpredictable and random. The hair may grow back at any time and then may fall out again. The extent of hair loss and regrowth varies greatly from person-to-person.