Discriminating Multisystem Inflammatory Syndrome in Children Requiring Treatment from Common Febrile Conditions in Outpatient Settings

J Pediatr. 2021 Feb;229:26-32.e2. doi: 10.1016/j.jpeds.2020.10.013. Epub 2020 Oct 13.


Objectives: To examine whether patients with multisystem inflammatory syndrome in children (MIS-C) demonstrated well-defined clinical features distinct from other febrile outpatients, given the difficulties of seeing acute care visits during the severe acute respiratory syndrome coronavirus 2 pandemic and the risks associated with both over- and underdiagnosis of MIS-C.

Study design: This case-controlled study compared patients diagnosed with and treated for MIS-C at a large urban children's hospital with patients evaluated for fever at outpatient acute care visits during the peak period of MIS-C. Symptomatology and available objective data were extracted. Comparisons were performed using t tests with corrections for multiple comparisons, and multivariable logistic regression to obtain ORs.

Results: We identified 44 patients with MIS-C between April 16 and June 10, 2020. During the same period, 181 pediatric patients were evaluated for febrile illnesses in participating outpatient clinics. Patients with MIS-C reported greater median maximum reported temperature height (40°C vs 38.9, P < .0001), and increased frequency of abdominal pain (OR 12.5, 95% CI [1.65-33.24]), neck pain (536.5, [2.23-129,029]), conjunctivitis (31.3, [4.6-212.8]), oral mucosal irritation (11.8, [1.4-99.4]), extremity swelling or rash (99.9, [5-1960]), and generalized rash (7.42, [1.6-33.2]). Patients with MIS-C demonstrated lower absolute lymphocyte (P < .0001) and platelet counts (P < .05) and greater C-reactive protein concentrations (P < .001).

Conclusions: Patients treated for MIS-C due to concern for potential cardiac injury show combinations of features distinct from other febrile patients seen in outpatient clinics during the same period.

Keywords: Kawasaki disease; SARS-CoV-2; multisystem inflammatory syndrome in children; myocarditis.

MeSH terms

  • Adolescent
  • Age Factors
  • Ambulatory Care*
  • COVID-19 / complications*
  • COVID-19 / diagnosis*
  • COVID-19 / therapy
  • Child
  • Child, Preschool
  • Diagnosis, Differential
  • Female
  • Fever / diagnosis*
  • Fever / etiology*
  • Humans
  • Male
  • Retrospective Studies
  • Symptom Assessment
  • Systemic Inflammatory Response Syndrome / complications*
  • Systemic Inflammatory Response Syndrome / diagnosis*
  • Systemic Inflammatory Response Syndrome / therapy

Supplementary concepts

  • pediatric multisystem inflammatory disease, COVID-19 related