Therapeutic comparison between treatments for Vulvar Lichen Sclerosus: study protocol of a randomized prospective and controlled trial

BACKGROUND Vulvar lichen sclerosus (VLS) is a lymphocyte-mediated disease of unknown etiology that can cause intense itching as well stenosis, hindering the evacuation and urination. It can also limit the sex life due to severe local pruritus, pain and dyspareunia (pain during sexual intercourse). The standard treatment for this disease is the use of topical corticosteroids to reduce the clinical symptoms and to try to increase disease-free intervals. Photodynamic therapy (PDT), a treatment that associates a light radiation with a photosensitizing agent and photobiomodulation (PBM) are therapies that can promote effective immunomodulatory responses at the application site by means of photophysical and photochemical phenomena from the molecular to the systemic level, which promote their use in chronic dermatoses. The aim is to compare the effects of PDT, PBM, and topical corticosteroid in VLS evaluating clinical, histological, immunohistochemical and spectroscopic responses. METHODS The study is prospective, randomized and controlled, in a population of 60 women with histological diagnoses of VLS. There will be 3 treatments groups: PDT, PBM and topical corticosteroid (control group), where will be allocated by randomization 20 patients in each one. The clinical course will be monitored by measuring local temperature, itching, atrophy, and the area of the lesion. Histologically, the slides will be classified and will have the ordering of collagen fibers quantified. Immunohistochemical analysis will be done using the markers IFN-γ, TGF-β, CD4, CD8, IL-1, p53 and Ki-67. Finally, the spectroscopic evaluation will be done by reflectance. Descriptive and inferential statistical analyses will be conducted to compare the groups and make associations between different responses. The study is an open-label for patients with active symptomatic disease with a period of 1 year follow-up to determine the rate of recurrence in each groups. DISCUSSION The immunological effects of PDT and PBM are described by several authors in inflammatory skin diseases, stimulating the production and organization of the associated collagen. Thus, it is reasonable to determine the efficacy and safety of these new treatments in VLS, in comparison to the control group, analyzing the recurrence time, the impact on the optical properties of the skin, and the benefit to patients. TRIAL REGISTRATION ClinicalTrials.gov: NCT02416531 .