Table 4.

Case definitions of PIMS-TS (or MIS-C).

	Population	Clinical signs and symptoms	Evidence of multiorgan involvement	Markers of inflammation	Evidence of other infections	Evidence of SARS-CoV-2 infection	Additional comments
World Health Organization (30)	Children and adolescents 0–19 years of age	Fever > 3 days And two of the following:∧ Rash or bilateral non-purulent conjunctivitis or muco-cutaneous inflammation signs (oral, hands, or feet). Hypotension or shock. Acute gastrointestinal problems (diarrhea, vomiting, or abdominal pain)	Features of myocardial dysfunction, pericarditis, valvulitis, or coronary abnormalities, including echocardiogram findings or elevated Troponin/NT-proBNP Evidence of coagulopathy (by PT, APTT, elevated d-Dimers)	Elevated markers of inflammation such as erythrocyte sedimentation rate, C-reactive protein, or procalcitonin	No other obvious microbial cause of inflammation, including bacterial sepsis, staphylococcal, or streptococcal shock syndromes	Evidence of COVID-19 (RT-PCR, antigen test, or serology positive), or likely contact with patients with COVID-19
Center of Disease Control and Prevention (CDC) (US) (29)	An individual under 21 years	Presenting with fever The CDC note the fever should be at least 38 degrees Celsius for at least 24 h or a subjective fever lasting 24 h	Evidence of clinically severe illness requiring hospitalization with multisystem (>2) organ involvement (cardiac, renal, respiratory, hematologic, gastrointestinal, dermatologic, or neurological)	Evidence of inflammation could include but is not limited to an elevated C-reactive protein, erythrocyte sedimentation rate, fibrinogen, procalcitonin, d-dimer, ferritin, lactic acid dehydrogenase, or interleukin 6, elevated neutrophils, reduced lymphocytes, and low albumin	No alternative plausible diagnoses	Positive for current or recent SARS-CoV-2 infection by reverse-transcriptase polymerase chain reaction, serology or antigen test; or COVID-19 exposure within the 4 weeks prior to the onset of symptoms	Some individuals may fulfill full or partial criteria for Kawasaki disease but should be reported if they meet the case definition for MIS-C Consider MIS-C in any pediatric death with evidence of SARS-CoV-2 infection
Royal College of Pediatrics and Child Health (UK) (28)	Any child	Persistent fever	Evidence of single or multi-organ dysfunction (shock, cardiac, respiratory, renal, gastrointestinal or neurological disorder) with other additional clinical, laboratory or imagining, and ECG features	Neutrophilia, elevated CRP, and lymphopaenia	Exclusion of any other microbial cause, including bacterial sepsis, staphylococcal or streptococcal shock syndromes, infections associated with myocarditis such as enterovirus	SARS-CoV-2 PCR testing positive or negative	Children fulfilling full or partial criteria for Kawasaki disease may be included

^∧Two of the following of clinical signs and symptoms, or evidence of multiorgan involvement.