COVID-19 Resource Center

COVID-19 Resource Center

Perspective from David Cennimo, MD
Disclosures: The authors report no relevant financial disclosures.
November 27, 2021
3 min read

MIS-C cases more severe in second wave, study finds

Perspective from David Cennimo, MD
Disclosures: The authors report no relevant financial disclosures.
You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

We were unable to process your request. Please try again later. If you continue to have this issue please contact

Patients with multisystem inflammatory syndrome in children experienced more severe illness during a second wave of cases compared with the first, according to a study published in The Pediatric Infectious Disease Journal.

The CDC defines multisystem inflammatory syndrome in children (MIS-C) as a condition in any patient aged 21 years or younger who presents with fever, laboratory evidence of inflammation, evidence of clinically severe illness requiring hospitalization, with two or more organs involved, who has no alternative plausible diagnosis and has tested positive for current or recent SARS-CoV-2 infection, or reports exposure to a suspected or confirmed case of COVID-19. A similar syndrome also can occur in adults.

Source: Adobe Stock
Source: Adobe Stock.

Ashraf S. Harahsheh, MD, FACC, FAAP, a cardiologist at Children's National Hospital in Washington, and colleagues managed two pediatric cohorts of patients with MIS-C, following surges of COVID-19 cases in the U.S.

The first cohort consisted of 43 patients who were hospitalized between March and October 2020, whereas the second was composed of 63 patients hospitalized between November and April 2021.

“We’ve now seen three distinct waves of MIS-C since the beginning of the pandemic, each wave following national spikes in cases,” Roberta DeBiasi, MD, chief of pediatric infectious diseases at Children's National and a coauthor of the study, said in a news release.

“Kids in the second wave cohort had potentially experienced intermittent and/or repeated exposures to the virus circulating in their communities,” DeBiasi said. “In turn, this may have served as repeated triggers for their immune system, which created the more severe inflammatory response.”

Among a total of 106 patients from both waves, 46% were female, 54% were Black, 39% were Hispanic and the median age was 8.4 years (range, 4.7-13.4). No underlying medical conditions were found in 80 patients (75%).

Compared with patients hospitalized during the first wave, patients hospitalized during the second wave included a higher proportion of older children (21% vs. 5%), and they were more likely to present with shortness of breath (18% vs. 3%) but less likely to test positive for SARS-CoV-2 (16% vs. 49%).

Participants hospitalized during the second wave were also more likely than those in the first wave to require vasopressors (73% vs. 51%) and were less likely to use only a high-flow nasal cannula (10% vs. 26%).

“Despite the increased degree of clinical severity and laboratory abnormalities in the [second] cohort, no significant differences were noted comparing wave 2 and wave 1 cohorts,” the authors wrote.