Mechanisms Underlying Lichen Planus in Association with Biologic Therapy

Alexa S Podolsky,1 Shari R Lipner2 1Renaissance School of Medicine, Stony Brook University, New York, NY, USA; 2Department of Dermatology, Weill Cornell Medicine, New York, NY, USACorrespondence: Shari R Lipner, Department of Dermatology, Weill Cornell Medicine, 1305 York Ave 9th Floor, New York, NY, 10021, USA, Tel +1 6469623376, Fax +1 6469620033, Email [email protected]: Cutaneous reactions, including lichen planus (LP) and related lichenoid eruptions have been increasingly reported in association with biologic therapies including immune checkpoint inhibitors and tumor necrosis factor-α inhibitors. Since the immunologic mechanisms underlying biologic-associated LP remain unclear, we aimed to summarize current evidence on biologic-induced LP, outline implicated drug classes, and propose mechanistic models. We conducted a comprehensive systematic analysis of PubMed literature, reviewing 145 publications that identified 157 cases of biologic-associated LP and proposed several overlapping immunological mechanisms, including cytokine imbalances, T cell immune pathway shifts, antigen unmasking, keratinocyte apoptosis dysregulation, and host susceptibility. Management of biologic-associate LP includes withdrawal of the offending biologic and adjunctive treatment. Further research is needed to clarify mechanistic pathways, define incidence, and identify predictive biomarkers that may guide risk stratification.Keywords: lichen planus, lichenoid eruption, drug reaction, biologic therapy, immunologic mechanisms