Prevalence of vulval lichen planus in a cohort of women with oral lichen planus: an interdisciplinary study.

BACKGROUND Lichen planus (LP) is a mucocutaneous inflammatory dermatosis that frequently involves the oral and genital mucosae. Patients with LP affecting these sites are often seen by oral medicine specialists or gynaecologists who work in isolation and depend heavily on histopathologists to help them in confirming the diagnosis. There are few studies in the literature combining the experiences of these specialists who share the care of patients with both oral and genital LP. OBJECTIVES To estimate the prevalence of vulval LP (VLP) in a cohort of patients with histologically confirmed oral LP (OLP). METHODS The study group consisted of 42 women histologically diagnosed with OLP. The mean age was 60.5 years (range 27-81). They underwent genital examination, colposcopy and vulvoscopy. For the histological confirmation of clinical VLP biopsies were performed whenever a clinical lesion was found. Oral and genital biopsy specimens were processed through histological and immunohistochemical staining. Histological diagnoses of LP were made according to the modified World Health Organization histopathological criteria proposed by van der Meij and van der Waal for the diagnosis of OLP, and extended to VLP. Patients with clinical evidence, but without the histological confirmation of OLP and VLP, were excluded from the study group. RESULTS Thirty-two vulval and one vaginal biopsy specimens were obtained. Histological diagnoses were confirmed in 24 of 32 (75%) patients who underwent a vulval biopsy: these represent 57% (24 of 42) of the study group. Of the 12 patients free of symptoms such as itching, burning and dyspareunia, but with clinical vulval lesions, 11 (92%) had histological confirmation of VLP. Vulval lichen sclerosus was ascertained in five of 32 (16%) cases. CONCLUSIONS This study showed a 57% prevalence of VLP in selected patients with OLP. The high prevalence of VLP of 92% in the women who were free of vulval symptoms confirmed the usefulness of this careful integrated approach.