what autoimmune disease causes hair loss

Alopecia areata is an autoimmune disease that causes hair loss. In this condition, the immune system mistakenly attacks hair follicles, which are the structures in the skin that form hair. The attack on a hair follicle causes the attached hair to fall out, resulting in patchy hair loss that can vary in extent. Alopecia areata is often unpredictable, and hair may grow back and fall out again later. While the exact cause of alopecia areata is unknown, it is believed that a persons genetic makeup may trigger the autoimmune reaction, along with a virus or a substance the person comes into contact with. Certain autoimmune diseases, such as psoriasis, thyroid disease, or vitiligo, are also linked to alopecia areata.