Haemophagocytic lymphohistiocytosis (HLH) is a condition of uncontrolled immune activation caused by genetic defects or triggered by infections, malignancies, autoimmune diseases, drugs, pregnancy or post-transplant immunosuppression. This case describes a young man presenting with clinical jaundice and abnormal blood tests, including raised inflammatory markers, abnormal liver function, low haemoglobin (65 g/L) and a low white blood cell count (3.08×10