Clinical Presentation and Diagnostic Patterns of Multisystem Inflammatory Syndrome in Children in a Pediatric Emergency Department.

INTRODUCTION

Multisystem inflammatory syndrome in children (MIS-C) is a severe postinfectious complication of COVID-19, and diagnosis remains challenging because of overlapping features with other illnesses. We sought to describe emergency department (ED) evaluations of children with suspected MIS-C at a southeast Wisconsin pediatric referral center and to identify factors that distinguish MIS-C from alternative diagnoses.

METHODS

This retrospective study included children evaluated for MIS-C in the Children's Wisconsin ED from July 2020 through December 2022. We compared clinical and laboratory characteristics of children diagnosed with MIS-C with those of children with alternative diagnoses and used logistic regression to identify factors associated with MIS-C.

RESULTS

Among 792 children evaluated, 86 (11%) were diagnosed with MIS-C; case counts declined over time. Children with MIS-C were older (median age, 7.4 vs 2.9 years; P < .001) and had greater odds of cardiac (OR, 50.4; 95% CI, 27.4-96.4), mucocutaneous (OR, 3.57; 95% CI, 2.18-6.04), gastrointestinal (OR, 2.36; 95% CI, 1.36-4.36), and hematologic (OR, 8.81; 95% CI, 5.41-14.4) system involvement than children with other diagnoses. Odds of MIS-C were reduced among children with a positive non-COVID-19 viral test (OR, 0.12; 95% CI, 0.02-0.41), but alternative diagnoses made before the ED visit were not associated with MIS-C risk.

CONCLUSIONS

In this cohort of children evaluated for MIS-C in southeast Wisconsin, specific symptoms aligned with MIS-C diagnostic criteria were associated with increased odds of MIS-C, whereas positive non-COVID-19 viral tests were associated with alternative diagnoses. These findings may assist clinicians in risk stratification and diagnostic decision-making for children with suspected MIS-C in the emergency department setting.