Clinical Manifestations of Multisystem Inflammatory Syndrome in Children Following COVID-19: A Narrative Review

Coronavirus 2 acute and severe respiratory infection virus (SARS-CoV2) has been identified as a pathogen of COVID-19 disease. Initially it was thought that children were safe from the virus, but several reports showed Multisystem Inflammatory Syndrome in Children (MIS-C) as a dangerous complication of COVID-19. There are similarities and differences between MIS-C and Kawasaki disease, Kawasaki shock syndrome, and toxic shock. It is a multisystem disease that affects major systems, including cardiovascular, respiratory, blood and coagulation, kidney, and nervous systems. Diagnosis of MIS-C is based on evidence of recent SARS-CoV2 infection and multiple system involvement, and laboratory criteria for high inflammation in the absence of other causes. In many of these patients chest imaging may show no evidence of COVID-19 involvement, or abnormal findings such as pleural effusion, ground glass patchy opacities, or local density and atelectasis may be seen. Echocardiography shows involvement of pericardium, myocardium, endocardium, and coronary arteries, which may be accompanied by cardiac arrhythmias. On abdominal imaging, evidence of ascites may be reported in these patients. In whole blood tests, lymphopenia, anemia, and thrombocytopenia are common, and inflammatory markers are very high. In mild cases, patients can be closely monitored, but many of these children develop severe forms and require hospitalization or pediatric intensive care unit. This study narratively reviews the clinical manifestations of multisystemic inflammatory syndrome in children following COVID-19.