Systematic review on the clinical presentation and management of the COVID-19 associated multisystem inflammatory syndrome in children (MIS-C)

Firstly, we collated the vast repository of MIS-C cases and presented them in a simplified, condensed, and comprehensive format. Secondly, we explored the clinical presentation, and efficacy of the management options. Additionally, we briefly discussed the pathophysiology and addressed the variance in the jargon and criteria relating to this condition. Methods: A systematic literature review was conducted on the 17th of October 2020 in accordance with PRISMA (2015) guidelines. The search terms: 'MIS-C', 'Kawasaki-like Disease', `PIMS-TS', and `COVID-19' were queried on Medline and Embase databases. Publications that fulfilled the inclusion criteria were included and were assessed for parameters pertaining to the clinical course and management. Results: From December 2019 to October 2020, 131 publications were identified. Of these, 56 publications (n = 646 patients) fit the inclusion criteria. Median age was 10 years (range: 0.5-17 years), 52.2% (n = 337/646) were male, and 33.5% (n = 128/382) were of African ethnicity. SARS-CoV-2 reverse transcriptase PCR and serology were positive in 42% (n = 142/426), and 85.3% (n = 300/352) of cases respectively. Presenting complaint(s) were predominately gastrointestinal: 77.6% (n = 436/562) generalized abdominal pain, 76.4% (n = 386/505) vomiting, and 63.2% (n = 203/321) diarrhea. Hypotensive shock was also commonly observed at admission. Additionally, laboratory data revealed elevated neutrophils and inflammatory markers. Echocardiogram findings indicated reduced left ventricular ejection fraction and myocarditis in 22.6% (n = 85/376) and 22.3% (n = 84/376) of cases, respectively. Immunoglobulins and intravenous steroids were predominantly used in 76% (n = 433/571) and 51% (n = 317/618) of cases, respectively. Majority of the patients (97%, n = 418/431) were discharged home. A combination treatment of tocilizumab and IVIG had a mean length of stay of 7 +/- 3 days and 95.5% (n = 21/22) discharge rate with low complications in comparison to either of the treatments alone. Conclusion: MIC-S syndrome is a pediatric hyperinflammatory condition that has an association with COVID-19 background exposure. MIS-C has a heterogeneous multisystem presentation that can be associated with life threatening cardiac complications. There is a need to further explore its long-term morbidity.