Reactive hemophagocytic syndrome presenting as a component of multiple organ dysfunction syndrome

Objective: To report two cases of severe reactive hemophagocytic syndrome ( RHS), to discuss their impact, and to present evidence that RHS may be a co nstitutive part of multiple organ dysfunction syndrome (MCDS), Design: Case-report, Setting: Pediatric intensive care unit (PICU), Patients: Two patients with RHS and MODS, Interventions: None. Measurements and Main Results: Case #1: A 3 yr-old boy with Mucha-Haberman syndrome (pityriasis lichenoides) was admitted to the PICU for septic shock , acute respiratory distress syndrome, capillary leak, acute renal failure, liver dysfunction, and RHS (pancytopenia and hemophagocytosis on bone marr ow aspirate). The pancytopenia was severe (white blood cell count, 0.9 x 10 (9)/L; hemoglobin, 59 g/L; platelets, 36 x 10(9)/L), required many transfus ions, and resolved 2 months later. The patient needed mechanical ventilatio n for 6 wks, Length of stay in PICU was 2 months. Case #2: A previously hea lthy 4 yr-old girl was admitted to the PICU for respiratory failure. She de veloped acute respiratory distress syndrome, cardiomyopathy with complete a trioventricular block, shock, capillary leak, liver dysfunction, and RHS (p ancytopenia and hemophagocytosis on bone marrow aspirate), The pancytopenia was severe (white blood cell count, 1.92 x 10(9)/L; hemoglobin, 65 g/L; pl atelets, 58 x 10(9)/L) and necessitated transfusional support. Serology for respiratory syncytial virus was positive. RHS duration was 20 days; the pa tient recovered completely. Length of mechanical ventilation was 16 days an d length of stay in PICU was 3 wks, Conclusions:These cases show that RHS may be a significant cause of pancyto penia in the PICU, It needs to be recognized as a clinical entity because i t can be reversible and nonneoplastic. RHS and MODS share some pathophysiol ogic elements and could be related to each other.