Hemophagocytic lymphohistiocytosis at initiation of kawasaki disease and their differential diagnosis.

The authors report a case of hemophagocytic lymphohistiocytosis that became apparent and was confirmed by a specific Th1/Th2 cytokine pattern at the initiation of Kawasaki disease in an 18-month-old child. His condition deteriorated fast and produced no response to intravenous immunoglobulin and dexamethasone. A standard HLH-2004 regimen was started. But he developed respiratory failure, seizure, and cardiac arrest, and died. This case is unique for developing hemophagocytic lymphohistiocytosis at the initiation of Kawasaki disease, with fatal outcome. This case may indicate a yet unknown mechanism triggers these 2 diseases; a specific Th1/Th2 cytokine pattern helps rapid differential diagnosis between these 2 diseases.