Lichen sclerosus et atrophicus
1. What every clinician should know
Lichen sclerosus is a chronic disorder of the skin, most commonly seen on the vulva. Extragenital lesions are seen in 5-20% of patients. Typical lesions of lichen sclerosus are porcelain-white papules and plaques, often seen in conjunction with areas of ecchymosis or purpura. The skin typically appears whitened, thinned and crinkling (‘cigarette paper’ in appearance).
Although the genital mucosa is spared, lesions at the mucocutaneous junction can lead to introital narrowing. Perianal involvement is common (giving rise to a ‘figure of eight’ or ‘hourglass’ distribution of disease). Other findings include distortion of the vulvar architecture, characterized often by labial fusion, fissures and phimosis of the clitoral hood.
Although lichen sclerosus can be seen at any age, the mean age of onset is 50-60 years. Women are affected more commonly then men. The etiology remains unknown, although evidence points in the direction of a genetic and/or autoimmune disorder. For example, in a large observational cohort study of over 1,000 women with lichen sclerosus, 12% had a positive family history of LS. Support for the latter theory stems from the frequent association of other autoimmune disorders such as alopecia, vitiligo, thyrotoxicosis, hypothyroidism and pernicious anemia in patients with lichen sclerosus.
Because of the chronic itching and scratching seen in women with lichen sclerosus, this population remains at increased risk of vulvar carcinoma. Although patients most commonly report pruritus, other symptoms such as irritation, burning, dyspareunia and tearing are frequently found.
Because lichen sclerosus can be asymptomatic, the true prevalence of the disease remains unknown. Prevalence estimates range from 1:60 to 1:1,000.
2. Diagnosis and differential diagnosis
Clinically, early lichen sclerosus can be subtle. In this case, the patient presented with localized itching, which correlated with a small focus of hyperkeratosis on the left vulva. Upon further inspection, it should be noted that the left labium minor is also attenuated. In the patient with advanced disease, the labia minora are now completely fused with phimosis of the clitoral hood.
To confirm the diagnosis of lichen sclerosus, a biopsy should be performed. It should be noted, however, that while histology often reveals epidermal atrophy with loss of rete ridges, hyperkeratosis and a band-like inflammatory dermal infiltrate with homogenization of dermal collagen, histology may be inconclusive even in the setting of advanced disease.
In light of the association between autoimmune disorders and lichen sclerosus, a brief examination for alopecia areata and vitiligo is reasonable. Thyroid function testing can be considered, although there are no clear recommendations regarding evaluation for coexisting autoimmune disorders in this patient population.
Common mimics of lichen sclerosus include vitiligo, severe vulvovaginal atrophy, other lichenification disorders such as lichen planus and lichen simplex chronicus, vulvar intraepithelial neoplasia, and vulvar squamous cell carcinoma. For this reason, biopsy is recommended. In cases where the diagnosis is unclear, referral to a vulvar specialist is recommended.
The recommended treatment for lichen sclerosus is a high potency topical steroid ointment, the most studied of which is clobetasol proprionate. In a number of randomized controlled trials, clobetasol consistently resulted in higher rates of symptom remission and in some patients, improvement in skin appearance, compared to a number of other topical medications (e.g., progesterone and testosterone).
While there is no evidence regarding the most effective steroid regimen, a reasonable approach is to begin with once-daily application until symptoms resolve, then tapering the frequency of administration. Initially, monitoring at three months and six months following initiation of therapy is recommended to assess the patient’s response to therapy, ensure proper application, and assess side effects. For patients with well-controlled lichen sclerosus, annual visits are reasonable, with more frequent visits reserved for patients with poorly controlled disease.
The need for maintenance therapy has been debated. While some experts recommend ongoing maintenance with once-weekly use of an ultrapotent or moderate strength topical steroid, others advocate the use of topical steroids only for flares or recurrent symptoms. In rare cases, patients fail to respond or cannot tolerate topical steroid application.
For poorly controlled disease, intralesional steroid injections may also be helpful. Topical calcineurin inhibitors have also been found to be effective in the treatment of lichen sclerosus. While promising, reports of a possible link to skin cancer and lymphoma based on animal studies led the FDA in 2005 to recommend topical immunosuppressant calcineurin inhibitors be used as second-line agents for short-term and intermittent treatment for patients who are unable to use other treatments. Surgical management of lichen sclerosus is reserved exclusively for women with malignancy or postinflammation sequelae (e.g., severe introital narrowing).
Long-term complications include progression of vulvar distortion (e.g., labial fusion, phimosis of the clitoral hood, introital narrowing) and an increased risk of vulvar carcinoma (4-6%, a significantly increased risk compared to age-matched women without vulvar lichen sclerosus). Despite adequate treatment, women with lichen sclerosus continue to experience significant sexual dysfunction (i.e., dyspareunia, decreased orgasm and decreased coital frequency).
Ultrapotent steroid therapy can be complicated by not only skin changes (e.g., dermal atrophy), but also the possibility of adrenal suppression with overuse of topical therapy. Patients should therefore be carefully counseled regarding frequency of application. Use of the topical calcineurin inhibitors avoids the risk of dermal atrophy, although as noted above, these agents should only be used as second-line treatment.
5. Prognosis and outcome
While topical steroid therapy is clearly beneficial in terms of symptom control, there is little evidence that its long-term use or optimal control of symptoms reduces the risk of malignancy. Because lichen sclerosus confers an increased risk of vulvar malignancy, long-term follow-up is required. Persistent or suspicious lesions (e.g., ulcerations, masses) should be biopsied in order to exclude intraepithelial neoplasia or invasive squamous cell cancer.
6. What is the evidence for specific management and treatment recommendations?
Burrows, LJ, Creasey, A, Goldstein, AT. “The treatment of vulvar lichen sclerosus and female sexual dysfunction”. J Sex Med. vol. 8. 2011. pp. 219-22. (Little is known about the impact of medical therapy and sexual function among women with lichen sclerosus. Embedded within a RCT of clobetasol versus pimecrolimus for lichen sclerosus, the study authors found that even among women with symptom improvement on therapy, sexual dysfunction persisted.)
“Diagnosis and management of vulvar skin disorders. ACOG Practice Bulletin No. 93. American College of Obstetricians and Gynecologists”. Obstet Gynecol. vol. 111. 2008. pp. 1243-53. (Thorough, well-researched review of a variety of common vulvar disorders including lichen sclerosus.)
Jones, RW, Sadler, L, Grant, S. “Clinically identifying women with vulvar lichen sclerosus at increased risk of squamous cell carcinoma: a case-control study”. J Reprod Med. vol. 49. 2004. pp. 808-11. (Predicting vulvar carcinoma in women with lichen sclerosus is difficult. Jones et al found that neither presence nor duration of symptoms or loss of vulvar architecture predicts risk.)
Murphy, R. “Lichen sclerosus”. Dermatol Clin. vol. 28. 2010. pp. 707-15. (Excellent, up-to-date and thorough review of LS by one of leading scholars in this area.)
Neill, SM, Lewis, FM, Tatnall, FM, Cox, NH. “British Association of Dermatologists. British Association of Dermatologists' guidelines for the management of lichen sclerosus 2010”. Br J Dermatol. vol. 163. 2010. pp. 672-82. (Provides most recent evidence-based guidelines for the management of lichen sclerosus.)
Sherman, V, McPherson, T, Baldo, M, Salim, A, Gao, XH, Wojnarowska, F. “The high rate of familial lichen sclerosus suggests a genetic contribution: an observational cohort study”. J Eur Acad Dermatol Venereol. vol. 24. 2010. pp. 1031-4. (Large observational cohort of patients with lichen sclerosus revealed increased risk of vulvar carcinoma among women with a family history of lichen sclerosus, but no increased risk of autoimmune disorders.)
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