Lichen sclerosus is estimated to occur in one to three per 1,000 patients referred to dermatologists. In the most vulnerable group of patients, women aged 50 to 59 years, the incidence may be 14 cases per 100,000 per year. Because many patients remain undiagnosed, the true incidence, prevalence and etiology of this condition remain unclear. A review by Powell and Wojnarowska stresses the importance of recognizing the anogenital forms of lichen sclerosus and its variety of presentations.

Over 80 percent of cases of lichen sclerosus involve the anogenital area. Women report intractable pruritis and soreness of the vulval and perianal areas leading to dysuria, pain on defecation and dyspareunia. The skin may appear atrophic or hyperkeratotic, but is usually fragile with telangiectasia, erosions, fissures and tears. Eventually, scarring may fuse the labia, bury the clitoris and distort the introitus. In prepubertal girls, the lesions may be mistaken for symptoms of sexual abuse. However, sexual abuse and lichen sclerosus can coexist. In men, the perianal area may be spared, but the glans penis and foreskin are usually severely affected. The tissues appear pale and atrophic, and distortion results in poor urinary stream. Other patients may be asymptomatic.

The cause of lichen sclerosus is unknown, but genetic, autoimmune and traumatic etiologies have been suggested. The condition has also been linked to infection, particularly with human papillomavirus and borrelia spirochetes. Biopsy is often performed to rule out other conditions. The histologic features of lichen sclerosus characteristically show inflammatory changes at all levels of the skin. An estimated 5 percent of cases of lichen sclerosus in women progress to vulval squamous cell carcinoma.

Treatment with potent topical steroids provides relief of symptoms. Clobetasol proprionate 0.05 percent may be used twice daily for up to three months, then tapered, depending on patient response. Topical testosterone (2 percent) has been used frequently but has not been effective in controlled clinical trials and is associated with androgenic side effects. Patients also require significant information and support services. Analgesic and other symptomatic treatments, such as stool softeners, local emollients and lubricants, may also be indicated. Male and female patients may require surgery to correct scarring deformities, and all patients should be continuously monitored because of their risk of developing malignancy.