Multisystem inflammatory syndrome in children (MIS-C) is the most severe pediatric disease associated with COVID19 for which the optimal therapeutic strategy remains unknown. There have been studies that aim to describe treatment outcomes but have conflicting findings. Evidence is urgently needed to support treatment decisions for MIS-C.

This study aims to compare the effectiveness of intravenous immunoglobulins (IVIG) plus corticosteroids versus IVIG alone as initial therapy in MIS-C, in terms of decrease in left ventricular dysfunction, decrease in inotropic support, reduced need for adjunctive immunomodulatory treatment, favorable fever course, decrease in mechanical ventilator use, decrease in admission to the pediatric intensive care unit, and decrease in coronary artery aneurysm.

Published articles reporting MIS-C treatment outcomes were searched through various databases. A structured data extraction was employed and risk of bias was assessed with Newcastle-Ottawa Scale. Corticosteroid effects were reported as pooled odds ratio and forest plots were generated for each outcome.

The effect on the components of hemodynamic support showed no significant difference between the two treatment groups: left ventricular dysfunction (P -value= 0.86), inotrope use (P -value = 0.65), mechanical ventilator use (P -value = 0.21), and admission at the PICU (P -value = 0.87). However, initial treatment with IVIG plus corticosteroids, was associated with a more favorable fever course (P -value = < 0.02), less use of adjunctive immunomodulatory therapy (P -value = < 0.00001), and less incidence of coronary artery aneurysm (P -value = < 0.04).

Initial treatment with IVIG plus glucocorticoids was associated with a more favorable fever course, less use of adjunctive immunomodulatory therapy, and less incidence of coronary artery aneurysm than IVIG alone.