Table 1.

The CDC case definition for MIS-C

All four diagnostic criteria must be met:
1. Age <21 years
2. Clinical presentation should include all of the following:
a. Fever ≥38.0°C for ≥24 hours or report of subjective fever lasting ≥24 hours
b. Laboratory evidence of inflammation, including, but not limited to, one or more of the following:
• Elevated C-reactive protein (CRP)
• Elevated erythrocyte sedimentation rate (ESR)
• Elevated fibrinogen
• Elevated procalcitonin
• Elevated D-dimer
• Elevated ferritin
• Elevated lactic acid dehydrogenase (LDH)
• Elevated interleukin 6 (IL-6)
• Elevated neutrophils
• Reduced lymphocytes
• Low albumin
c. Evidence of clinically severe illness requiring hospitalization
d. Multisystem (≥2) organ involvement (cardiac, renal, respiratory, hematologic, gastrointestinal, dermatologic, or neurological)
3. No alternative plausible diagnoses
4. Positive for current or recent SARS-CoV-2 infection by RT-PCR, serology, or antigen test, or COVID-19 exposure within the 4 weeks before the onset of clinical manifestations

CDC, Centers for Disease Control; MIS-C, multisystem inflammatory syndrome in children; RT-PCR, reverse transcription polymerase chain reaction.

Source: United States Centers for Disease Control and Prevention. Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 (COVID-19). 2020. Available at: https://emergency.cdc.gov/han/2020/han00432.asp.