Investigators at multiple institutions conducted a case series to describe the characteristics of children with pediatric inflammatory multisystem syndrome (PIMS), also termed multisystem inflammatory syndrome in Children (MIS-C). Children were eligible if they were hospitalized in England between March and May 2020 and met criteria for PIMS/MIS-C as defined by the Royal College of Pediatrics and Child Health, the World Health Organization, or the CDC. Investigators abstracted clinical and laboratory features of cases from the medical record.
Cases were compared to patients with Kawasaki disease (KD) and KD shock syndrome, as well as patients with toxic shock syndrome (TSS). Patients with KD were seen between 2002 and 2019 at Rady Children’s Hospital in San Diego, CA. Patients with TSS were part of a European database of febrile children seen between 2012 and 2020.
There were 58 children who met PIMS/MIS-C criteria. Overall, 45 (78%) had evidence of current or prior SARS-CoV-2 infection. The median age was 9 years (range: 3 months-17 years). All patients with PIMS/MIS-C presented with persistent fever for 3 to 19 days with variable combinations of sore throat (10%), headache (26%), abdominal pain (53%), erythematous rashes (52%), lymphadenopathy (16%), mucous membrane changes (29%), and swollen hands and feet (16%). Pediatric intensive care was required for 50%, and shock requiring inotropic support was present in 47%. All patients had marked elevation of inflammatory markers, including CRP (median 229 mg/L). Blood, surface, and other site cultures were negative. Three clinical patterns were evident among patients: (a) a persistent fever and elevated inflammatory marker pattern without evidence of organ failure or mucocutaneous features suggestive of KD or TSS (39%); (b) shock, often associated with left ventricular dysfunction (50%); and (c) development of diagnostic criteria for KD (11%).
The comparison groups included 1,132 children with KD, 45 with KD shock syndrome, and 37 with TSS. Children with KD, KD shock, or TSS were younger (mean age of 2.7, 3.8, and 7.4 years, respectively) than children with PIMS/MIS-C. Children with PIMS/MIS-C also had higher CRP and white blood cell counts than children with KD or KD shock. Children with PIMS/MIS-C who met diagnostic criteria for KD also tended to be older and have higher CRP, ferritin, and troponin levels than children with KD.
The authors conclude that PIMS/MIS-C appears to be distinct from other pediatric inflammatory diseases.
Dr Higgins disclosed no financial relationship relevant to this commentary.
MIS-C/PIMS recently has been described in children, most with evidence of COVID-19 infection, resulting in rapidly worsening illness. Numerous articles describing presentation, treatment, and outcomes of such patients have been published in the last several months.1
Based on the current report and others, a portion of children with COVID-19 who develop MIS-C have...