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.2 Hematologic abnormalities such as anemia and lymphopenia have been reported in association with sarcoidosis, but sarcoidosis has rarely been reported with PV.3 Here we present a patient with PV and multiorgan sarcoidosis who experienced resolution of cutaneous sarcoidosis lesions after systemic JAK inhibitor therapy for PV.