[Unexplained fever and B-symptoms in a young male Black African].

An immunocompetent Nigerian developed a fulminant hemophagocytic lymphohistiocytosis due to Epstein-Barr virus reactivation. The patient initially presented with fever, hepatosplenomegaly and pancytopenia. The clinical status of our patient deteriorated quickly despite treatment with corticoids. Escalation of immunosuppressive treatment was not possible. He died of lung, liver and circulatory failure in our intensive care unit.Hemophagocytic lymphohistiocytosis is a rare disease characterized by inflammation due to prolonged and excessive activation of antigen-presenting cells. High plasma ferritin levels and phagocytosis of hematopoetic cells in bone marrow, spleen and liver lead to the diagnosis. Hemophagocytic lymphohistiocytosis should therefore be included in the differential diagnosis in patients with persistent fever, hepatosplenomegaly and cytopenia.