Hemophagocytic lymphohistiocytosis secondary to Ehrlichia chaffeensis infection: a case report.

Hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially life-threatening condition that is characterized by fever, splenomegaly, and cytopenia in 2 or more peripheral blood lineages, hypertriglyceridemia, hypofibrinogenemia, and hemophagocytosis. HLH may be primary or may be triggered by numerous etiologies, including infections. Identification of underlying etiology of HLH is important as proper treatment can completely resolve the disease process. We present a patient whose clinical presentation fulfilled the diagnostic criteria for HLH but whose illness was caused by infection with Ehrlichia chaffeensis, emphasizing the need to explore all possible etiologies during evaluation of patients presenting with illnesses consistent with HLH.