Alopecia is a chronic inflammatory disease that affects the hair follicles. It is the medical term derived from a classical Greek word that means hair loss. Autoimmune alopecia is hair loss due to the body’s immune system acting against its own tissue. The body’s immune system normally makes proteins called antibodies to protect the body against viruses, bacteria, and other foreign materials. These foreign materials are called antigens. In an autoimmune disorder such as alopecia, the immune system loses its ability to tell the difference between foreign substances ( antigens) and cells in the hair follicles. The immune system then makes antibodies directed against ’self’. This immune response causes chronic inflammation at the hair follicle.
Autoimmune alopecia affects around one million people in the UK. For most people alopecia does not cause any other physical symptoms except hair loss. Depending on genetic susceptibility others may present with multiple autoimmune diseases.
Types of Alopecia
Autoimmune alopecia is categorised by the pattern of hair loss and the area affected on the body. There are 3 types of autoimmune alopecia. The underlying process causing the hair loss is the same.
Areata means occurring in patches. It presents as areas of hair loss on the scalp and the beard area that are commonly circular. This can be a single patch or multiple areas. 10 – 20% of people with Autoimmune Alopecia that starts in patches go on to develop more extensive hair loss.
Totalis refers to complete hair loss of the scalp. It may or may not include facial hair loss such as the beard or eyelashes.
Universalis refers to complete hair loss of the entire body.