Abstract
Polyarteritis nodosa (PAN) is one of diseases which is difficult to diagnose, because it causes inflammation of medium arteries in multiple organs and produces a variety of symptoms. A 12-year-old boy was referred to our hospital, because he had a fever lasting seven days, weight loss and a markedly increased level of inflammatory reaction. Echocardiography performed on day 13 of illness revealed coronary artery dilatation, and he was diagnosed with atypical Kawasaki disease (KD) although no major symptoms other than fever and coronary artery lesions were observed. Predicted high-dose intravenous immunoglobulin (IVIG) therapy refractory, steroid was administrated in combination with IVIG followed by good response. Oral steroids were discontinued after administration for 17 days, but he had fever and increased inflammatory reaction again from the next day and we judged that KD had recurred. IVIG and ulinastatin were administered, and infliximab was further delivered to obtain pyretolysis, but the inflammatory reaction was not completely negative. Ultimately, he was diagnosed with PAN by FDG PET/CT imaging showing vasculitis of bilateral femoral arteritis, and cyclophosphamide pulse therapy was used in combination with steroid administration. Some cases with an atypical course of KD may require differentiation from other vasculitis syndromes such as PAN, and FDG PET/CT scans may be useful if the diagnosis cannot be made by CT angiography or other imaging tests.
