Identification of key symptoms for a core outcome set for research in vulvar lichen sclerosus: a CORALS symptom domain initiative

Background Genital lichen sclerosus (LS) is a chronic inflammatory skin disease affecting men, women and children. It is most common in females with estimated 1-3% of women affected across their lifetimes. Vulvar LS can cause significant symptoms and impact quality of life. To enhance the quality of clinical research and practice, core outcome domains have been identified including quality of life, clinical signs, and symptoms by the Core Outcome Set for Research in Lichen Sclerosus (CORALS) initiative. Objectives To identify key symptoms for the core outcome symptom domain for research in LS. Methods An international multidisciplinary steering committee of experts in vulvar, penile and pediatric LS was convened to define and discuss LS symptoms. A modified electronic Delphi process was conducted among experts to reach consensus on priority symptoms. An online patient survey was distributed to LS patient advocacy groups to rank symptoms. A scoping review was performed to identify commonly measured symptoms in LS studies in men, women, and children. Results from all three sources were analyzed and symptoms selected. Results The patient survey (n = 863) ranked itch, burning, pain, and cuts or tears in the skin as the most important symptoms, with pain with sex being most important to some, and least important to others. Ninety-nine percent of respondents to the survey identified as adult women, limiting generalizability to other populations with LS. Expert consensus identified five key symptoms: itch, pain with vaginal penetration, cuts and tears in the skin, pain, and irritation. The scoping review of 93 manuscripts showed itch, pain with penetration, and burning/burning pain as the most frequently measured symptoms. Itch emerged as the most important symptom across all three data sources, with pain also consistently prioritized. Conclusions This study identified five key symptoms for evaluating vulvar LS. Although designed to capture symptoms from all patients with LS, both the survey and scoping review included small populations of male and pediatric participants, highlighting the need for further research in this population. Based on the results, we suggest measurement of itch, pain, skin cuts and tears, burning, and (when relevant) pain with sex within the symptoms core outcome domain for vulvar LS. These findings will be used to inform content validity studies when evaluating potential measurement instruments for the COS.