Lichen sclerosus (LS) is a chronic cutaneous inflammatory disorder involving the anogenital region and, less commonly, other areas of the skin. Prevalence is unknown. There are two incidence peaks: in childhood and in adult females, with the mean annual incidence estimated at 1/900 females for each of these age groups. The female-to-male ratio is 6-10:1. Typically, patients present with white, smooth, atrophic plaques in the anogenital region with pallor, atrophy and possible distortion of anatomy. Erythema, hyperkeratosis, fissuring, ecchymosis, edema, and ulceration may also be present. An increased risk of squamous cell carcinoma has also been reported. Extragenital areas are also affected in 11-20% of the patients and may involve the trunk and neck, upper legs, the wrists and the scalp. Some patients may be asymptomatic. Females may present with vulvar itching, soreness, dysuria, burning sensations, dyspareunia, or constipation, while males may have difficulty retracting the foreskin which may lead to phimosis and sexual difficulties. Etiology is unknown. The condition may be influenced by genetic factors, as demonstrated by familial cases with autosomal dominant transmission, a family history of autoimmune disease and HLA associations. Associations of LS with autoimmune disorders and psoriasis have also been reported. Infections with Borrelia and human papilloma virus (HPV) have been implicated, as have immunological constitution and hormonal status, and local factors. The diagnosis is based on histological findings of biopsied tissue that may reveal thinning of the epidermis with flattening of the rete ridges, lichenoid infiltrate and hydropic degeneration of the basal cells, edema and homogenization of the collagen in the upper dermis. The epidermis may be hyperkeratotic and acanthotic as a result of chronic scratching. Differential diagnoses include lichen planus, mucous membrane pemphigoid, lichen simplex (see these terms), as well as vulvar intraepithelial neoplasia (VIN) and sexual abuse. Lichen sclerosus is usually treated with potent or very potent topical corticosteroids. Topical tacrolimus or pimecrolimus may help to control inflammation. Surgery is indicated for advanced scarring that causes dyspareunia, micturition problems or phimosis, and in case of malignancy. Support groups and a multidisciplinary approach are recommended. Management includes long-term follow-up of patients for early diagnosis of any potential malignancies. Many patients experience resolution of the symptoms and in a minority of cases the clinical signs also resolve. However, adult patients have a 2-5% higher risk of developing squamous cell carcinomas.
Last update: March 2009