Erosive lichen planus affecting the vulvovaginal region (ELPV) is a rare chronic inflammatory condition causing painful raw areas that can lead to scarring, at the vaginal entrance. Symptoms considerably impact upon daily function and quality of life. There is risk of cancerous change in affected skin of 1-3%. A Cochrane Systematic Review, published in 2012, found no randomised controlled trials (RCT) on which to base treatment for ELPV. Retrospective case series suggest that super-potent topical corticosteroids are frequently used as first-line therapy, although one third of patients fail to respond adequately and require escalation of therapy. There is clinical uncertainty regarding which second-line therapies should be used. The following steps were taken to inform the design of an RCT to determine optimal second-line therapy for EVLP resistant to topical steroids: • A multi-centre retrospective review and audit of case notes to assess current clinical management in the UK. • A qualitative investigation with UK clinicians to establish their views and principles of management of ELPV. • An international multi-disciplinary electronic-delphi consensus exercise to agree a set of diagnostic criteria for ELPV. • A systematic review to assess existing outcome measure tools that have been used in randomised controlled trials of vulval skin disorders. • Assessment of patients views through a survey of a national patient group and subsequent focus groups with patients. The resulting multi-centre, four-armed, open-label, pragmatic randomised controlled trial will compare hydroxychloroquine, methotrexate and mycophenolate mofetil against a standard care group of clobetasol propionate 0.05% plus a short course of oral prednisolone. This will be the first RCT to test systemic agents for patients with ELPV and will add to the existing evidence base. The methodologies employed to develop the RCT protocol, and the trial design itself, may act as a template for clinical research into the therapeutic management of other rare inflammatory conditions.