Abstract: Lichen planus is a common T cell-mediated autoimmune disease, and its pathogenesis is closely associated with the activation of the JAK-STAT signaling pathway. As a novel, highly selective JAK1 inhibitor, the application of ivarmacitinib in lichen planus has not been reported. Herein, we present a case of successful treatment of nail lichen planus complicated with agranulocytosis crisis with ivarmacitinib providing new insights for clinical decision-making.

Key words: ivarmacitinib, nail lichen planus, agranulocytosis, JAK1 inhibitor