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Lichen sclerosus (LS) is a chronic inflammatory dermatosis of the anogenital area that affects quality of life due to the severe itching. LS may also present with extragenital manifestations that are generally nonpruritic. Of note, vulvar disease seems to have an increased risk of squamous cell carcinoma, but the role of additional cofactors (e.g., human papillomavirus infection or prior radiotherapy) has not been defined.
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The incidence of LS has not been precisely determined. It has been estimated to be in the order of 14 per 100,000 persons per year.1 LS is more prevalent in females, accounting for a 5:1 gender ratio. It preferentially affects women in the fifth or sixth decade of life and children younger than the age of 10 years.1,2 Up to 15% of LS cases occur in children, particularly in girls, and one study reported a prevalence of 1 in 900 premenarchal girls.3 A 0.07% incidence in males has recently been determined in a study of 153,432 male soldiers.4 Among blacks and Hispanics, the incidence in this group was 1.06%, whereas the incidence was only 0.051% in white soldiers.4 LS seems to be a prominent cause of phimosis; in one study, 14% of adolescent boys had LS, whereas 40% of phimosis cases in adult men were associated with LS.5 Similarly, a recent study of foreskins examined after therapeutic circumcision for phimosis confirmed many cases of unrecognized LS.6 As genital LS in males is almost exclusively seen in uncircumcised men, the rate of circumcision in a given population has a strong impact on the occurrence of the disease.
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The cause of LS is unknown. While a genetic predisposition has generally not been found,7 a recent observational cohort study reported a high rate of familial LS cases.8 Of 1,052 females with LS, 126 (12%) had a positive family history of LS. Vulvar cancer was significantly increased in those patients with a family history of LS compared with those without (4.1% vs. 1.2%).8 This report proposes a likely genetic component in the etiology of LS. Evidence for the presumed infectious cause, such as ...