Multi-system Inflammatory Syndrome Presentation to the Pediatric Emergency Department

Background: In April 2020, the emergence of Multi-system Inflammatory Syndrome in Children (MIS-C) was first recognized. Existing studies have been mostly descriptive of the clinical characteristics associated with MIS-C. Studies concerning how MIS-C patients present to the Emergency Department (ED) are scarce. There are also few studies describing the progression of the disease during hospitalization and outcomes and comparing those who have severe versus non severe MIS-C.

Our study sought to confirm prior findings as well as investigate if abnormal laboratory values were associated with worse outcomes based on hospital placement (not requiring admission, admission to pediatric floor, and admission to pediatric intensive care unit [PICU]) as well outcomes at time of disposition.

Methods: This was a retrospective case-control study at a tertiary care pediatric children’s hospital in a metropolitan area. Medical records of patients diagnosed with MIS-C per the Center for Disease Control’s (CDC) or World Health Organization (WHO) criteria from March 2020 to June 2020 were reviewed. Control cases were defined as patients who met criteria for diagnosis of MIS-C but were found to be negative on COVID polymerase chain reaction (PCR) testing. To assess the differences between MIS-C patients discharged home from the ED and those admitted to the PICU regarding obesity neutrophilia, lymphopenia and elevated troponins, a Pearson’s Chi-square test was conducted. The total MISC population was studied to see if associated obesity, neutrophilia, lymphopenia or elevated troponins were associated with a worse outcome, a Fisher’s Exact test was conducted.

Results: There were no differences between those with MIS-C and controls in reference to age, gender and race. Comparing those who were admitted to the PICU versus that were discharged from the ED, or admitted to a non-PICU bed, we found a significant increase in neutrophilia and troponin I. A significant association with elevated troponin and obesity occurred when comparing the MIS-C group and controls. There was no association of obesity, neutrophilia, lymphopenia, and elevated troponin with poor outcome.

Conclusion: Children with neutrophilia and increased troponin I were associated with more severe illness requiring PICU admission. Despite these findings, their outcomes were not affected. When controls were compared to those with MIS-C there was a significant increase in elevated troponin and obesity. With these findings, ER physicians can expect worse illness based on neutrophilia and increased troponin I helping one to decide if a child needs to be admitted to the PICU.