 lichen sclerosus (ls) (also termed, incorrectly, "lichen sclerosus et atrophicus") is a disease of unknown cause that results in white patches on the skin, which may cause scarring on and around genital skin. there is a biomodal age distribution in the incidence of ls. it occurs in girls with an average age of diagnosis of 7.6 years in girls and 60 years old in women. the average age of diagnosis in boys is 9-11 years old. several risk factors have been proposed, including autoimmune diseases, infections and genetic predisposition. there is evidence that ls can be associated with thyroid disease. ==signs and symptoms==  women are more commonly affected than men (10 to 1 ratio), particularly around and after menopause, but younger women or girls may also develop the disease. the condition most commonly occurs on the vulva and around the [[anus]
Ailments_of_unknown_etiology Lichenoid_eruptions