Group G streptococcal endocarditis-associated hemophagocytic syndrome.

We report the case of a 28-year-old previously healthy male who presented with a 1-week history of fever, headache, vomiting, and jaundice. Blood cultures were positive for group G streptococci and transesophageal echocardiography demonstrated vegetations on the aortic valve, leading to a definitive diagnosis of infective endocarditis. The combination of fever, splenomegaly, anemia, thrombocytopenia, hypertriglyceridemia, elevated ferritin level, low natural killer (NK) cell activity, and hemophagocytosis in bone marrow aspirate confirmed the diagnosis of hemophagocytic syndrome (hemophagocytic lymphohistiocytosis). Antibiotic treatment and intravenous immunoglobulins were administered and the patient made a full recovery.