Table 1.

Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 (COVID-19)

MIS-C case definition

1. Individual < 21 years old presenting with fever ≥ 24 h, laboratory evidence of inflammation, and evidence of clinically severe illness requiring hospitalization, with multisystem (≥ 2) organ involvement (cardiac, renal, respiratory, hematologic, gastrointestinal, dermatologic, or neurological); AND

2. No alternative plausible diagnosis; AND

3. Positive for current or recent SARS-CoV-2 infection by RT-PCR, serology, or antigen test; or COVID-19 exposure within the 4 weeks prior to symptom onset

Organ system involvement

Cardiac: shock, elevated troponin, elevated pro-BNP, coronary arteritis, abnormal echocardiogram, arrhythmia

Gastrointestinal: severe abdominal pain, vomiting, diarrhea, elevated transaminases

Hematologic: elevated d-dimers, coagulopathy, lymphopenia, thrombocytosis or thrombocytopenia

Mucocutaneous: petechia or purpura, polymorphous rash, mucositis, conjunctivitis

Neurologic: headache/irritability, altered mental status, seizures, focal neurologic deficits

Respiratory: acute respiratory distress syndrome, pulmonary embolism

Renal: acute kidney injury or failure

Laboratory evidence of inflammation

Elevated C-reactive protein, sedimentation rate, fibrinogen, procalcitonin, d-dimer, ferritin, lactic acid dehydrogenase

Elevated interleukin-6

Elevated neutrophils

Reduced lymphocytes

Low albumin

BNP brain natriuretic peptide; RT-PCR reverse transcription-polymerase chain reaction; SARS-CoV-2 severe acute respiratory syndrome coronavirus 2. (Adapted from [9])