Relapse of nephrotic syndrome triggered by Kawasaki disease.

Minor infections, allergies, insect bites, and bee stings are commonly reported causes of nephrotic syndrome (NS). Herein, we report, to the best of our knowledge, the first case of NS relapse due to Kawasaki disease (KD). An 8-year-old boy presented with high fever of 4-day duration. He had developed steroid-dependent NS at the age of 4 years and remained in remission after steroid and mizonbin therapy. Renal biopsy, performed at the age of four, showed minimal change (MC) disease. Upon examination, the patient fulfilled 5 of 6 criteria for KD under the Japanese diagnostic guidelines, with positive proteinuria. He was diagnosed with NS relapse caused by KD. Proteinuria resolved after treatment with intravenous immunoglobulin and cyclosporine A. We present the case of an 8-year-old boy, whose NS relapsed due to KD. To the best of our knowledge, this is the first case report. It is necessary to recognize that KD can trigger relapse of MCNS.