Kawasaki Disease and Pediatric Multisystem Inflammatory Syndrome in the Aftermath of the Pandemic

Abstract

Following the initial months of the COVID-19 pandemic, Multisystem Inflammatory Syndrome in Children (MIS-C) was identified as an entity associated with SARS-CoV-2 infection. In addition to the viral epidemiological shift, many factors contributed to MIS-C being exceptionally rare today. The similarities to other diseases previously described in the pediatric population have made its clinical management challenging in the post-pandemic era. However, given its potential severity, it is essential to incorporate the different phenotypes into the diagnostic and therapeutic approach to common pediatric diseases and syndromes to minimize both underdiagnosis and overtreatment. The Kawasaki disease phenotype of MIS-C (fKD/MIS-C) and Kawasaki disease (KD) require special attention, as they share multiple clinical and pathophysiological characteristics. While the current evidence on KD is robust regarding treatment, severity, and outpatient follow-up, MIS-C management relies predominantly on expert recommendations. It is crucial to recognize the key common and distinctive features of these entities to optimize diagnosis, identify at-risk groups, and improve therapy during the acute phase and outpatient follow-up. Nonetheless, the long-term implications of fKD/MIS-C have not yet been fully elucidated.