Resolution of cutaneous sarcoidosis after Janus kinase inhibitor therapy for concomitant polycythemia vera

Sarcoidosis is a chronic multisystem inflammatory disorder characterized by the formation of immune granulomas that may lead to serious, often irreversible, disability and significant disease-associated mortality.1 Current understanding suggests that sarcoidosis represents a helper T cell 1–mediated granulomatous immune response to an unidentified antigen, but the exact pathogenesis remains unknown.1 Polycythemia vera (PV) is an acquired myeloproliferative neoplasm characterized by mutant Janus kinase 2 (JAK2) signaling leading to erythrocyte overproduction.