Alopecia circumscripta is a typical autoimmune condition that frequently causes irregular hair loss. The majority of the time, hair thinning occurs in little patches about the size of a quarter. Alopecia circumscripta may just cause a few patches, but it can also affect larger regions of the scalp.
White blood cells that target the cells in hair follicles give rise to the condition by causing them to constrict and drastically slow down hair development. It is unclear why the immune system of the body specifically targets hair follicles in this manner.
Currently, alopecia circumscripta is incurable, although there are several forms of treatment that doctors might recommend to enhance the growth of new hair.