Epidemiology and clinical manifestations

Lichen sclerosus is recognized most often on the vulva of postmenopausal women, with prepubertal girls representing a significant minority. Lichen sclerosus is seen in all age groups, but it is often less symptomatic in premenopausal and postpubertal females who do not have the additive effect of an atrophic, hypoestrogenic vagina. Lichen sclerosus occurs very occasionally on the glans penis of men, and it occurs rarely as an isolated finding on extragenital skin in either gender.

Lichen sclerosus is a common disease, reported in about 3% of incontinent women in a nursing-home environment ¹. Another survey discovered that 1.7% of women presenting to a gynecologist’s office were found to have lichen sclerosus². In addition, a vulvar clinic in England found lichen sclerosus to be the most common disease evaluated and treated, occurring in 39% of those patients³. There is a slight familial tendency, but the risk for the development of lichen sclerosus in family members is not known.

Itching is the most common presenting symptom of women with lichen sclerosus. Pruritus is frequently excruciating, and scratching often produces tearing and purpura because the affected skin is extremely fragile. The patient then experiences pain from the erosions, particularly with urination, sexual activity, or with attempted sexual activity. Pain with defecation due to fissured perianal lichen sclerosus, and resulting fecal retention and constipation are common, particularly in young girls.

Classically, well-developed lichen sclerosus presents as sharply demarcated white plaques encompassing the modified mucous membranes of the vulva, perineal body, and perianal skin (Figure 14.1). Most often, lichen sclerosus begins around the clitoral hood but, despite prominent involvement of the perineal body and perianal skin, it does not generally affect the keratinized, hair-bearing labia majora (Figures 14.2 and 14.3). Distant extragenital disease has been reported in a minority of women. A series of 250 women examined in this author’s office showed 6% with extragenital disease of keratinized skin and no oral or vaginal lesions (abstract still in press; presented at XIX World Congress of International Society for the study of Vulvovaginal Disease, July 2007, Alaska). The most common locations for extragenital disease are upper arms, back, and chest (Figure 14.4). Lichen sclerosus usually, but not always, spares the mucous membrane of the vestibule, and it has been reported only rarely in the mouth⁴. There is only one report of vaginal lichen sclerosus⁵. Lesions of the mouth or the vagina suggest an alternative or additional diagnosis.

Figure 14.1 Classic lichen sclerosus manifested by a white, sharply demarcated plaque encompassing the modified mucous membranes as well as the perineal body; the skin is shiny and crinkled with loss of the labia minora and partial agglutination of the clitoral hood.

Figure 14.2 Lichen sclerosus preferentially affecting the periclitoral skin and the perineal body.

Figure 14.3 The periclitoral area is often the first area affected, and edema and smooth, shiny skin are early skin changes of lichen sclerosus.

Figure 14.4 The extragenital lichen sclerosus on this woman was on her upper back, and shows the crinkled texture and purpura typical for this disease.

Although many skin diseases present with white skin on moist mucous membranes or modified mucous membranes, the hallmark of lichen sclerosus is a characteristic texture change of the white plaques. Although the pathognomonic texture change is that of a crinkling or cellophane paper-type appearance, some lesions exhibit a smooth, waxy surface, and others manifest nonspecific irregular, hyperkeratotic white skin (Figures 14.5–14.7). Rubbing and scratching sometimes produce thickening of the skin (lichenification) and superimposed lichen simplex chronicus can obscure diagnostic texture changes of the lesions (Figure 14.8). Fragility is a hallmark of lichen sclerosus, manifested by purpura, erosions, and fissuring (Figures 14.9–14.12). Extragenital lesions show even more striking texture changes because of the dry nature of the skin. Sometimes, follicular plugging is visible in these lesions.

Figure 14.5 This cellophane paper crinkling of perianal skin is nearly pathognomonic for lichen sclerosus.

Figure 14.6 Smooth, hypopigmented, nearly waxy skin also occurs in some women with lichen sclerosus, as has occurred on the medial labia majora of this patient.

Figure 14.7 More long-standing disease is likely to manifest as hyperkeratotic or macerated skin. The perineal body is an area especially prone to thickened lichen sclerosus.

Figure 14.8 Superimposed thickening and purpura from rubbing have occurred in this patient.

Figure 14.9 Purpura in the setting of white, crinkled skin is classic for lichen sclerosus.

Figure 14.10 Fissures are common in women with lichen sclerosus, especially within natural skin folds.

Figure 14.11 The thin, fragile skin of lichen sclerosus is more prone to inflammation, fissuring, erosion, and secondary infection as a result of minor irritants. This patient has a secondary staphylococcal skin infection.

Figure 14.12 Irregular erosions in this patient with lichen sclerosus were produced by scratching.

Long-standing and severe disease is associated with resorption of vulvar architecture, with loss of the labia minora, and the clitoris is buried under the scarred clitoral hood (Figures 14.13 and 14.14). Sometimes, side-to-side anterior and/or posterior adhesions eventuate in narrowing of the introitus (Figure 14.15). Squamous cell carcinoma occurs in up to 5% of women with untreated lichen sclerosus (Figure 14.16)⁶. The primary risk factors for the development of squamous cell carcinoma are elderly age of patients (probably an indication of longer duration of disease) and the presence of hyperkeratotic lesions (Figure 14.17)⁷.

Figure 14.13 Agglutination of the labia minora and partial agglutination of the clitoral hood often occur in advanced lichen sclerosus.

Figure 14.14 Ongoing agglutination is clear on the anterior vulva of this woman with lichen sclerosus.

Figure 14.15 Anterior midline agglutination of the vulva has produced early narrowing of the introitus.

Figure 14.16 This 89-year-old woman with excruciatingly pruritic undiagnosed lichen sclerosus presented with this painful nodule, found to represent an invasive squamous cell carcinoma on biopsy.

Figure 14.17 Recalcitrant hyperkeratotic lichen sclerosus is the morphology most at risk for transformation into squamous cell carcinoma.

Lichen sclerosus is sometimes associated with patchy hyperpigmentation of the modified mucous membranes and vestibule (Figure 14.18). This pigment change ranges from mild, poorly demarcated, tan patches to wild, irregular, variegate brown and black patches indistinguishable from malignant melanoma. Pigmentary changes are nearly always benign, but biopsy and follow-up are prudent, since case reports of atypical nevi and melanoma in the setting of lichen sclerosus suggest that there may be an association⁸^–¹⁰. Also, benign pigmented lesions in the setting of vulvar lichen sclerosus sometimes appear atypical histologically, confounding the differentiation of benign from malignant¹¹.

Figure 14.18 Patchy hyperpigmentation is very common in lichen sclerosus, most visible after therapy.

Women with lichen sclerosus have an increased prevalence of hypothyroidism ¹², and many clinicians find that their lichen sclerosus patients appear to be more likely to exhibit concomitant vitiligo or lichen planus, although data are scant^13,¹⁴.