Improvement of drug-induced twenty-nail dystrophy with upadacitinib therapy

Twenty-nail dystrophy is an uncommon disorder characterized by rough, brittle nails and may occur secondary to inflammatory diseases or medications. We report a patient with suspected leflunomide-induced twenty-nail dystrophy refractory to medication withdrawal and intralesional corticosteroids who demonstrated gradual, sustained improvement following initiation of upadacitinib for seronegative rheumatoid arthritis. This case highlights a potential role for JAK inhibition in chronic inflammatory nail matrix disease and expands the spectrum of nail disorders that may respond to targeted immunomodulatory therapy.