Epidemiology and Clinical Outcomes of Refractory Kawasaki Disease in South Korea

Abstract

Refractory Kawasaki disease (KD) is defined as KD resistant to initial intravenous immunoglobulin (IVIG) therapy. The proportion of refractory KD is reported to be 10%−20%, and the risk of coronary arterial aneurysm (CAA) is increased in refractory KD. We analyzed data of Korean nationwide surveys on KD to know the epidemiology, treatment modalities, and clinical outcomes of refractory KD in South Korea. We analyzed the data of three triennial Korean nationwide surveys on KD from 2009 to 2017, and selected patients with refractory KD who had persistent or recrudescent fever at least 36 hours after completion of initial IVIG therapy. Among a total of 42,705 KD patients from 2009 through 2017, 5,581 (13.1%) had refractory KD. The annual proportions of refractory KD were between 10.1% and 18.7%, which showed significant changes with the nadir in 2013 and increased proportions in 2015−2017 (P < 0.05). Treatment modalities for refractory KD were second IVIG in 86.2%, third or more IVIG in 3.8%, corticosteroids in 34.4%, infliximab in 3.7%, methotrexate in 1.0%, plasmapheresis in 0.1%, and cyclosporine in 0.02%. The use of third or more IVIG showed a decreasing trend, and the use of corticosteroids and infliximab showed an increasing trend. The incidence of CAA was significantly higher in refractory KD patients than in total KD patients (5.5% vs 1.8%; P < 0.05). The overall proportion of refractory KD was 13.1% from 2009 through 2017 in South Korea. The annual proportions of refractory KD showed significant changes with increased proportions in recent years. Treatment modalities for refractory KD showed a decreasing trend in the use of third or more IVIG and an increasing trend in the use of corticosteroids and infliximab. The incidence of CAA was significantly higher in refractory KD patients than in total KD patients.