Lack of oral involvement in a large cohort of women with vulvar lichen sclerosus – a multicenter prospective study

Background and Objectives: We assessed the prevalence of oral lichen sclerosus in a cohort of women affected with vulvar lichen sclerosus (VLS). Patients and Methods: This prospective, observational study included adult female patients with a histologically proven VLS who attended the Vulva Clinics of three Dermatology Units from January 2020 to July 2023. During this period, all VLS patients were asked to be examined in their oral cavities in order to detect any possible sign of oral diseases, which were then biopsied. Results: Three hundred women (mean age 64.5 ± 13.0 years) were included, of whom 21 (7%) had a concurrent extragenital LS. In six (2%) patients, white, non-removable lesions were found at oral inspection and biopsied. All cases were histologically lichen planus. No other clinically relevant oral lesions were found. The six women with histologically proven oral lichen planus had more frequent periodontal and autoimmune diseases than the other included subjects. Conclusions: Our findings confirm the absolute rarity of oral involvement in patients with VLS. They suggest that the oral mucosa, unlike the genitals, is a setting which weakly leads to development of LS, also in predisposed subjects.