Lichen sclerosus (LS) refers to a benign, chronic, progressive dermatologic condition characterized by marked inflammation, epithelial thinning, and distinctive dermal changes accompanied by symptoms of pruritus and pain (picture 1A-C) . The previous designation was lichen sclerosus et atrophicus; the "et atrophicus" was dropped because areas of thickening and hyperplasia often occur. LS usually occurs in the anogenital region (85 to 98 percent of cases), but can develop on any skin surface [2,3]. Extragenital lesions are present in 15 to 20 percent of patients.
The clinical manifestations, diagnosis, and management of vulvar LS will be reviewed here. Extragenital LS and LS involving the male genitalia are discussed separately. (See "Extragenital lichen sclerosus" and "Balanitis and balanoposthitis in adults", section on 'Lichen sclerosus or balanitis xerotica obliterans'.)
Vulvar LS can occur at any age but tends to have two peaks of onset: prepubertal girls and perimenopausal or postmenopausal women . It is one of the most common conditions treated in vulvar clinics. The true prevalence is not known; estimates range from 1 in 30 elderly women to 1 in 59 women in a general gynecology practice to 1 in 300 to 1000 patients referred to dermatologists [5-9].
The etiology of lichen sclerosus (LS) is unknown. A number of mechanisms have been proposed based upon epidemiologic data:
●Genetic factors — Familial aggregations of LS among fathers and daughters, mothers and daughters, sisters, and twins (identical and fraternal) have been reported [10-12]. Trauma, injury, and sexual abuse may trigger symptoms in genetically predisposed individuals, which suggests presence of the Koebner phenomenon (ie, development of isomorphic pathologic lesions in the traumatized uninvolved skin of patients who have a cutaneous disease) .