Table 1.

Case definition of inflammatory syndrome in children

Royal College of Paediatrics and Child Health, United Kingdom, May 1, 2020	Child presenting with: •Persistent fever > 38.5 °C •Laboratory evidence of inflammation (eg: neutrophilia, elevated CRP, lymphopenia) •Single or multi-organ dysfunction •Exclusion of alternative causes •SARS-CoV-2 testing can be positive or negative
Centers for Disease Control and Prevention, United States, May 14, 2020	Individual aged < 21 y presenting with: •Fever (≥ 38 °C or subjective) for at least 24 h •Evidence of inflammation (including but not limited to elevated CRP, ESR, fibrinogen, procalcitonin, D-dimer, ferritin, lactic acid dehydrogenase, or interleukin 6, elevated neutrophils, reduced lymphocytes, and low albumin) •Multisystem (≥ 2) organ involvement with evidence of clinically severe illness requiring hospitalization AND •No alternative plausible diagnosis AND •Positive for current or recent SARS-CoV-2 infection (RT-PCR, serology, or antigen) or exposure within 4 wk prior to symptom onset
World Health Organization, May 15, 2020	Individual aged ≤ 19 y with fever ≥ 3 d AND ≥ 2 of the following: •Rash, bilateral non-purulent conjunctivitis, or mucocutaneous inflammation signs •Hypotension or shock •Cardiac involvement (eg: myocardial dysfunction, pericarditis, valvulitis, or coronary abnormalities, elevated troponin, or elevated NT-proBNP) •Evidence of coagulopathy •Acute gastrointestinal problems AND •Elevated markers of inflammation (eg: ESR, CRP, or procalcitonin) AND •No other obvious microbial cause of inflammation AND •Evidence of COVID-19 infection (RT-PCR, antigen test, or serology) or likely contact with patients with COVID-19

COVID-19, coronavirus disease 2019; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; NT-proBNP, N-terminal pro-B-type natriuretic peptide; RT-PCR, reverse transcriptase polymerase chain reaction; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.