Multisystem inflammatory syndrome in children: A systematic review

Abstract

Background: Multisystem inflammatory syndrome in children (MIS-C), also known as pediatric inflammatory multisystem syndrome, is a new dangerous childhood disease that is temporally associated with coronavirus disease 2019 (COVID-19). We aimed to describe the typical presentation and outcomes of children diagnosed with this hyperinflammatory condition.

Methods: We conducted a systematic review to communicate the clinical signs and symptoms, laboratory findings, imaging results, and outcomes of individuals with MIS-C. We searched four medical databases to encompass studies characterizing MIS-C from January 1st, 2020 to July 25th, 2020. Two independent authors screened articles, extracted data, and assessed risk of bias. This review was registered with PROSPERO CRD42020191515.

Findings: Our search yielded 39 observational studies (n = 662 patients). While 71·0% of children (n = 470) were admitted to the intensive care unit, only 11 deaths (1·7%) were reported. Average length of hospital stay was 7·9 ± 0·6 days. Fever (100%, n = 662), abdominal pain or diarrhea (73·7%, n = 488), and vomiting (68·3%, n = 452) were the most common clinical presentation. Serum inflammatory, coagulative, and cardiac markers were considerably abnormal. Mechanical ventilation and extracorporeal membrane oxygenation were necessary in 22·2% (n = 147) and 4·4% (n = 29) of patients, respectively. An abnormal echocardiograph was observed in 314 of 581 individuals (54·0%) with depressed ejection fraction (45·1%, n = 262 of 581) comprising the most common aberrancy.

Interpretation: Multisystem inflammatory syndrome is a new pediatric disease associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that is dangerous and potentially lethal. With prompt recognition and medical attention, most children will survive but the long-term outcomes from this condition are presently unknown.

Funding: Parker B. Francis and pilot grant from 2R25-HL126140. Funding agencies had no involvement in the study.

Keywords: COVID-19; Children; Coronavirus disease 2019; Hyperinflammatory shock; MIS-C; Multisystem inflammatory syndrome in children; PIMS; Pediatric; Pediatric inflammatory multisystem syndrome; SARS-CoV-2; Severe acute respiratory syndrome 2.

Fig. 1

PRISMA flow diagram. Delineation of study selection.

Fig. 2

Overall clinical outcomes in individuals with MIS-C. All 662 patients were considered in these findings. ICU-intensive care unit, CXR-chest x-ray, AKI-acute kidney injury, ECMO-extracorporeal membrane oxygenation.

Fig. 3

Cardiovascular complications in individuals with MIS-C. Performed Echo (echocardiogram) is out of the whole population, n = 662. The denominator in electrocardiogram (EKG) was 89 and shortening fraction (SF) was 22, as this was the number of individuals reported to have those studies conducted or variables reported in their echocardiogram, respectively. The remaining cardiac findings included a sample of 581 pediatric cases of MIS-C (87•8% of 662 individuals).

Fig. 4

Comparison of the signs and symptoms of individuals with MIS-C versus COVID-19. Pediatric cases of MIS-C are depicted in gold, while children with COVID-19 are the solid blue bars. All 662 MIS-C patients were included in this analysis. The sample size for COVID-19 patients was 2445 patients for all the signs/symptoms, except for symptomatic (n = 2367).