Macrophage activation syndrome: Experience in the questioned role of etoposide.

Reactive hemophagocytic lymphohistiocytosis (HLH), or macrophage activation syndrome (MAS), is an unusual complication of systemic inflammatory diseases.1 Its association with juvenile idiopathic arthritis (JIA) is rare and treatment must be immediate. We report the case of a girl in whom we detected this association and treated it successfully with a drug that is not first-line therapy because of its potential adverse effects. The patient was a 9-year-old girl who had recently been diagnosed as having JIA. She was admitted to the hospital after a 3-day history of persistent fever (40 C) and generalized facial edema, presumably associated with methotrexate she was taking, a treatment that was interrupted. At admission, she was pale, had painful hepatosplenomegaly and an increase in the volume of several joints. Laboratory tests showed pancytopenia (hemoglobin 6.4 g/dL; 132,000 platelets/mm3 and 1080 neutrophils/mm3), prothrombin time and partial thromboplastin time were increased (16.8 and 59.2, respectively) and fibrinogen was decreased (164.7 mg/dL).