A 2-Year-Old Boy With Refractory Kawasaki Disease Who Developed a Giant Aneurysm After Successful Treatment With Infliximab

Kawasaki disease (KD) is the leading cause of systemic vasculitis syndrome in infants and in young children, although its cause has still not been elucidated. Coronary aneurysm (CA) is a major and important complication of KD. Patients resistant to intravenous immunoglobulin (IVIG) treatment are at a high risk of CA. Infliximab (IFX) is a chimeric monoclonal antibody that specifically binds to tumor necrosis factor-alpha (TNF-α) and has been successfully used in some cases of IVIG-refractory KD. However, optimal timing for the administration of IFX has not yet been determined. We present a case of a 2-year-old boy with IVIG-refractory KD who developed a giant right coronary artery (RCA) aneurysm after successful treatment with IFX. Treatment with IVIG (2 g/kg), prednisolone (PSL, 2 mg/kg/day), and aspirin (50 mg/kg/day) was initiated on day 2 because of the fulfillment of KD criteria. Additional IVIG (2 g/kg) and ulinastatin (20,000 U/kg) treatment on day 5 and intravenous administration of IFX (5 mg/kg) on day 9 effectively lowered the patient’s fever and improved laboratory data. However, the RCA continued to balloon into a giant CA, from 7.3 mm on day 9 to 14.3 mm in diameter at 2 months. IFX is one treatment option for IVIG-refractory KD. However, the timing and indication of IFX treatment should be carefully determined. Int J Clin Pediatr. 2019;8(2):45-50 doi: https://doi.org/10.14740/ijcp345