High-dose anakinra as treatment for macrophage activation syndrome caused by refractory Kawasaki disease in an infant.

We report a 12-week-old boy presenting with incomplete refractory Kawasaki disease (KD) complicated with macrophage activation syndrome (MAS). The infant presented with cerebral irritability, pain, tachypnoea and vomiting for 10 days. He did not fulfil any of the classic diagnostic criteria for KD. Pericardial effusion on echocardiography in addition to severe dilatation of the coronary arteries in combination with leucocytosis and raised acute phase reactants led to the diagnosis of incomplete KD. Treatment with intravenous immunoglobulin and aspirin was initiated but without any response. The condition was subsequently refractory to additional treatment with infliximab and high-dose methylprednisolone. His condition worsened, fulfilling the criteria for MAS. High-dose anakinra was initiated, and remission of the inflammation was achieved.