Table 1.
MIS-C diagnostic criteria.
| Criteria | CDC [3] | WHO [66] | RCPCH [67] |
|---|---|---|---|
| Age | <21 years | <19 years | All children (age not defined) |
| Fever | ≥38C for ≥24 h or subjective fever lasting ≥ 24 h | Fever ≥ 3 days | Persistent fever ≥ 38.5C |
| Clinical | Evidence of clinically severe illness requiring hospitalization, with multisystem organ involvement (≥2 of the following: cardiac, renal, respiratory, hematologic, GI, dermatologic, or neurologic) | At least 2 of the following: 1) Rash, conjunctivitis, mucocutaneous inflammation 2) Hypotension or shock 3) Cardiac involvement⁎ 4) Coagulopathy 5) Acute GI symptoms |
Single or multiorgan dysfunction and additional features⁎⁎ |
| Inflammation | At least one of the following: elevated CRP, ESR, fibrinogen, procalcitonin, D-dimer, ferritin, lactic acid dehydrogenase, IL-6, elevated neutrophils, reduced lymphocytes, low albumin | Elevated CRP, ESR, procalcitonin | Neutrophilia, elevated CRP, and lymphopenia |
| SARS-CoV-2 | 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 | Positive for current or recent SARS-CoV-2 infection by RT-PCR, serology, or antigen test, or likely COVID-19 exposure | Positive or negative RT-PCR |
| Exclusion | No alternative diagnosis | No obvious microbial cause | Exclusion of other infections |
CDC, Centers for Disease Control and Prevention; WHO, World Health Organization; RCPCH, Royal College of Paediatric and Child Health; GI, gastrointestinal; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; IL-6, interleukin-6; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; RT-PCR, reverse transcription polymerase chain reaction; NT-proBNP, N-terminal pro-brain natriuretic peptide.
Cardiac involvement defined by the WHO MIS-C case definition: features of myocardial dysfunction, pericarditis, valvulitis, or coronary abnormalities (including echocardiogram findings or elevated troponin/NT-proBNP).
Additional features for the RCPCH definition: abdominal pain, confusion, conjunctivitis, cough, diarrhea, headache, lymphadenopathy, mucous membrane changes, neck swelling, rash, respiratory symptoms, sore throat, swollen hands and feet, syncope, vomiting.