Polyarteritis nodosa mimics Kawasaki disease.

Polyarteritis nodosa (PAN) is a rarely seen vasculitis that often affects small-sized and medium-sized arteries. PAN can present with diverse clinical features depending on the organs involved, including potential cardiac involvement. Typical cardiac manifestations of PAN in the paediatric age group include pericarditis, valvular heart disease and coronary artery aneurysms. In contrast to PAN, Kawasaki disease (KD) is often associated with coronary artery abnormalities. Herein, we report a case of a young boy presented with KD-like features, including a coronary artery aneurysm confirmed by an echocardiogram (ECHO) and eventually diagnosed as PAN. The patient was treated with steroids, methotrexate and tocilizumab with improvement of the symptoms. Repeated ECHO revealed the resolution of the coronary artery aneurysms. Our paper highlights a rare presentation of PAN mimicking KD presentation. Physicians should consider PAN in chronic or severe courses of KD or coronary artery aneurysms.