From sarcoidosis to cytokine storm: a case report of HLH induced by histoplasmosis and Epstein–Barr virus

Abstract Hemophagocytic lymphohistiocytosis (HLH) is a rare and potentially fatal inflammatory condition caused by uncontrolled activation of the immune system. It can be triggered by various factors and likely through infections, particularly Epstein-Barr virus, while fungal infections such as histoplasmosis are less frequently implicated in its occurrence. We present a case of a middle-aged immunocompromised male patient who initially exhibited progressive hepatic dysfunction due to hepatic histoplasmosis. The patient subsequently developed severe multiorgan dysfunction and fulfilled 7 out of the 7 HLH-2024 diagnostic criteria. Bone marrow biopsy supported the diagnosis of hemophagocytosis. The patient was treated with intravenous dexamethasone and liposomal amphotericin B for disseminated histoplasmosis. This case illuminates the importance of considering HLH in patients with a sudden and unexpected change in clinical status in chronic illness, including but not limited to histoplasmosis. Early recognition and identification of the underlying etiology are crucial for initiating timely and targeted therapy.