1) An individual aged < 21 years with the following criteria

2) Clinical criteria

_ A minimum 24-h history of subjective or objective fever _ 38.0˚C AND

_ Severe illness necessitating hospitalization AND

_ Two or more organ systems affected (i.e., cardiac, renal, respiratory, hematologic, gastrointestinal, dermatologic, neurological)

3) Laboratory evidence of inflammation

_ One or more of the following: an elevated CRP, ESR, fibrinogen, procalcitonin, D-dimer, ferritin, LDH, or IL-6; elevated neutrophils or reduced; low albumin

4) Laboratory or epidemiologic evidence of SARS-CoV-2 infection

_ Positive SARS-CoV-2 testing by RT-PCR, serology, or antigen OR

_ COVID-19 exposure within 4 weeks prior to onset of symptoms

5) No alternative diagnosis

Abbreviations: CDC, Centers for Disease Control; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; LDH, lactate dehydrogenase; RT-PCR, reverse transcriptase polymerase chain reaction; SARS-CoV-2, severe acute respiratory syndrome coronavirus-2