Severe Lactic Acidosis in an Infant with Haemophagocytic Lymphohistiocytosis

Haemophagocytic lymphohistiocytosis (HLH) is a rare disease with high mortality. We report a one-month-old infant presented with fever, pancytopenia, liver derangement, coagulopathy, and was subsequently diagnosed to have HLH. No secondary cause could be identified after extensive workup. She developed multi-organ failure with severe lactic acidosis that was refractory to other treatment. Continuous renal replacement therapy successfully corrected her lactic acidosis. Our case highlights the importance of monitoring serum lactate level in critically ill patients with severe metabolic acidosis.