Overview of lichen planus pathogenesis and review of possible future therapies

Abstract

Lichen planus (LP) is a chronic immune-mediated inflammatory disorder affecting approximately 0.5% to 1% of the population. It presents in various subtypes, including cutaneous LP, oral LP, genital LP, and lichen planopilaris. The pathogenesis of LP remains incompletely understood, involving a complex interplay of environmental triggers and genetic predispositions. The disease is primarily driven by T-cell-mediated cytotoxic mechanisms, with the involvement of the Janus kinase-STAT and IL-17 pathways playing a significant role. Current treatment options are limited, with high-potency topical corticosteroids as the first line for most patients, while more resistant cases require systemic immunosuppressants or biologics. Recent advances in immunomodulatory therapies, including Janus kinase inhibitors such as baricitinib and ruxolitinib and IL-17 inhibitors like secukinumab and ixekizumab, have shown promise in clinical trials, offering potential new treatment avenues. Emerging therapies, including erythropoietin gel and paeoniflorin, are also being explored. This review provides an in-depth exploration of the pathogenic mechanisms underlying LP and offers an updated overview of ongoing clinical trials investigating novel therapeutic agents targeting the immunopathogenic mechanisms of LP. The study emphasizes the need for targeted treatments to address the recalcitrant nature of the disease and its associated morbidity.