Cicatricial alopecias are classified as primary or secondary. This discussion is confined to the primary cicatricial alopecias, in which the hair follicle is the target of a destructive inflammatory process. In secondary cicatricial alopecias, destruction of the hair follicle is incidental to a non-follicle-directed process or external injury, such as severe infections, burns, radiation, or tumors.
Primary cicatricial alopecia refers to a diverse group of rare disorders that destroy the hair follicle, replace it with scar tissue, and cause permanent hair loss. Hair loss can be gradual, without symptoms, and unnoticed for long periods. In other cases, the hair loss may be associated with severe itching, pain and burning, and progress rapidly. Cicatricial alopecia occurs in otherwise healthy men and women of all ages and is seen worldwide.