L66: Cicatricial alopecia [scarring hair loss]

L66.3: Perifolliculitis capitis abscedens

Your hair roots are inflamed because a lot of sebum has been excreted by the surrounding sebaceous glands. When hair roots are persistently inflamed, they become damaged. New hair can no longer grow there. Only small areas are affected by the hair loss.

Pus-filled cysts often form on the scalp, in the armpits, or in the groins. The cysts may also seclude and press into the tissue. Tiny tunnels below the skin are typical of the condition. If you press on those areas, pus or a watery, bloody fluid usually leaks out. Deep scars are often left behind.

The cause of this disorder is unknown. Certain bacteria probably play a part.