ABSTRACT
Kawasaki syndrome (KS) is an acute vasculitis in children complicated by the development of heart disease. Despite its description over 50 years ago, the etiology of coronary artery disease in KS is unknown. High dose intravenous immunoglobulin is the most effective approach to reduce cardiovascular complications. It remains unclear why patients with KS develop coronary artery aneurysms. A subset of patients is resistant to immunoglobulin therapy. Given the heterogeneity of clinical features, variability of history, and therapeutic response, KS may be a cluster of phenotypes triggered by multiple infectious agents and influenced by various environmental, genetic, and immunologic responses. The cause of KS is unknown, and a diagnostic test remains lacking. A better understanding of mechanisms leading to acute KS would contribute to a more precision medicine approach for this complex disease. In the current viewpoint, we make the case for microbial superantigens as important causes of KS.