Journal Club

MIS-C: A Distinct New Inflammatory Process in Children Associated with SARS-CoV-2

Reviewed by Terri Stillwell, M.D.

In late April, cases of a multisystem inflammatory syndrome in children (MIS-C), or pediatric inflammatory multisystem syndrome (PIMS), as it is called in the U.K., began to be reported in areas with high SARS-CoV-2 prevalence. These cases appeared to be temporally associated with SARS-CoV-2 infection. In three recent articles, authors describe the spectrum of disease seen in some of the early cases.

Two of the studies focus on pediatric patients admitted to a New York City hospital, while the other comments on patients admitted to various hospitals in England. Initial reported symptoms seemed akin to Kawasaki’s disease (KD), however, these studies denote a spectrum of disease with findings distinct from KD.

In a JAMA research letter, Cheung et al. describe 17 patients with MIS-C, all of whom had fever and a majority of whom had gastrointestinal (GI) and mucocutaneous findings. Thirteen of the patients had shock and 15 required ICU care. Though some of the clinical presentations seemed similar to KD, or even toxic shock syndrome (TSS), the presence of lymphopenia, bandemia, increased troponins, B-type natriuretic peptide, and various cytokine markers make MIS-C appear different from KD. Miller et al., in an article in Gastroenterology, further describe a cohort of 44 MIS-C patients, where 84% of patients presented with GI symptoms and 70% had rash. GI symptoms are less often seen in KD-like disease.

In the U.K. study, reported in JAMA, Whittaker et al. compare recent PIMS cases to previous cases of KD, KD shock syndrome, and TSS. Predominant symptoms in this 58-patient cohort included: persistent fever, abdominal pain, and rash; 50% of these patients required ICU-level care. Seventy-eight percent had evidence of SARS-CoV-2 infection. While 13 patients met criteria for KD, when comparing this cohort of patients to other pediatric inflammatory processes, those with PIMS tended to be older with more significant markers of inflammation and increased evidence of cardiac injury.

The SARS-CoV-2 pandemic has brought to light a new inflammatory process in pediatric patients. While having some overlapping features with other inflammatory processes, MIS-C seems to be a distinct entity. Additional studies are needed to understand the underlying pathophysiology.

(Cheung et al. JAMA. Published online: June 8, 2020.)

(Miller et al. Gastroenterology. Published online: June 4, 2020.)

(Whittaker et al. JAMA. Published online: June 8, 2020.)