Table 3. Case definition of multisystemic inflammatory syndrome in children in South Korea

1. An individual aged ≤ 19 years presenting with fever > 38.0℃ for ≥ 24 hours, laboratory evidence of inflammation (elevated ESR, CRP, fibrinogen, procalcitonin, d-dimer, ferritin, LDH, or interleukin 6 and elevated neutrophils, reduced lymphocytes and low albumin), and evidence of clinically severe illness requiring hospitalization, with multisystem (> 2) organ involvement (cardiac, renal, respiratory, hematologic, gastrointestinal, dermatologic or neurological); AND2. No other obvious microbial cause of inflammation (bacterial sepsis, streptococcal/staphylococcal toxic shock syndrome, enteroviral myocarditis, etc.); AND3. Positive for current or recent SARS-CoV-2 infection by RT-PCR, serology, or antigen test; or exposure to a suspected or confirmed COVID-19 case within the 4 weeks prior to the onset of symptoms.

ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; LDH: lactate dehydrogenase; PCR: polymerase chain reaction.