. 2021 Feb 25;21(2):13. doi: 10.1007/s11882-020-00986-6

Table 2.

CDC and WHO preliminary case definition criteria for the multisystem inflammatory syndrome (or disorder) in children

Centers for Disease Control and Prevention (CDC) (55••)	World Health Organization (56)
An individual aged < 21 years presenting with fever,ⁱ laboratory evidence of inflammation,ⁱⁱ and evidence of clinically severe illness requiring hospitalization, with multisystem (≥ 2) organ involvement (cardiac, renal, respiratory, hematologic, gastrointestinal, dermatologic or neurological) *And* No alternative plausible diagnoses *And* 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 the onset of symptoms	Children and adolescents 0–19 years of age with fever ≥ 3 days *And* two of the following: 1. Rash or bilateral non-purulent conjunctivitis or mucocutaneous inflammation signs (oral, hands or feet) 2. Hypotension or shock 3. Features of myocardial dysfunction, pericarditis, valvulitis, or coronary abnormalities (including ECHO findings or elevated troponin/NT-proBNP) 4. Evidence of coagulopathy (by PT, PTT, elevated D-dimers) 5. Acute gastrointestinal problems (diarrhea, vomiting, or abdominal pain) *And* Elevated markers of inflammation such as ESR, C-reactive protein, or procalcitonin *And* No other obvious microbial cause of inflammation, including bacterial sepsis and staphylococcal or streptococcal shock syndromes *And* Evidence of COVID-19 (RT-PCR, antigen test, or serology positive) or likely contact with patients with COVID-19

Centers for Disease Control and Prevention (CDC) (55••)

World Health Organization (56)

An individual aged < 21 years presenting with fever,ⁱ laboratory evidence of inflammation,ⁱⁱ and evidence of clinically severe illness requiring hospitalization, with multisystem (≥ 2) organ involvement (cardiac, renal, respiratory, hematologic, gastrointestinal, dermatologic or neurological)

And

No alternative plausible diagnoses

And

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 the onset of symptoms

Children and adolescents 0–19 years of age with fever ≥ 3 days

And two of the following:

1. Rash or bilateral non-purulent conjunctivitis or mucocutaneous inflammation signs (oral, hands or feet)

2. Hypotension or shock

3. Features of myocardial dysfunction, pericarditis, valvulitis, or coronary abnormalities (including ECHO findings or elevated troponin/NT-proBNP)

4. Evidence of coagulopathy (by PT, PTT, elevated D-dimers)

5. Acute gastrointestinal problems (diarrhea, vomiting, or abdominal pain)

And

Elevated markers of inflammation such as ESR, C-reactive protein, or procalcitonin

And

No other obvious microbial cause of inflammation, including bacterial sepsis and staphylococcal or streptococcal shock syndromes

And

Evidence of COVID-19 (RT-PCR, antigen test, or serology positive) or likely contact with patients with COVID-19

ⁱFever ≥ 38.0 °C for ≥ 24 h or report of subjective fever lasting ≥ 24 h

ⁱⁱIncluding, but not limited to, one or more of the following: an elevated C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), fibrinogen, procalcitonin, D-dimer, ferritin, lactic acid dehydrogenase (LDH), or interleukin 6 (IL-6), elevated neutrophils, reduced lymphocytes, and low albumin