Table 1.
Preliminary case definitions for MIS-C
| MIS-C associated with COVID-19 | PIMS-TS | MIS-C associated with COVID-19 | Complete Kawasaki disease | Incomplete Kawasaki disease | Kawasaki disease shock syndrome | |
|---|---|---|---|---|---|---|
| Organisation or publication | WHO6 | Royal College of Pediatrics and Child Health39 | US Centers for Disease Control and Prevention37 | American Heart Association40 | American Heart Association40 | Kanegaye et al,41 |
| Age | 0–19 years | Child (age not specified) | <21 years | Child (age not specified) | Child (age not specified) | Child (age not specified) |
| Inflammation | Fever and elevated inflammatory markers for 3 days or more | Fever and elevated inflammatory markers | Fever and elevated inflammatory markers | Fever lasting 5 days or more* | Fever lasting 5 days or more* | Fever |
| Main features | Two of the following: (A) rash or bilateral non-purulent conjunctivitis or mucocutaneous inflammation signs (oral, hands, or feet); (B) hypotension or shock; (C) features of myocardial dysfunction, pericarditis, valvulitis, or coronary abnormalities (including echocardiogram findings or elevated troponin or N-terminal pro B-type natriuretic peptide); (D) evidence of coagulopathy (elevated prothrombin time, partial thromboplastin time, and elevated D-dimers); and (E) acute gastrointestinal problems (diarrhoea, vomiting, or abdominal pain) | Single or multiple organ dysfunction (shock or respiratory, renal, gastrointestinal, or neurological disorder; additional features (appendix 6 pp 3–4) | Clinically severe illness requiring hospitalisation; and multisystem (two or more) organ involvement (cardiac, renal, respiratory, haematological, gastrointestinal, dermatological, or neurological) | Four or more principal clinical features: (A) erythema and cracking of lips, strawberry tongue or oral and pharyngeal mucosa; (B) bilateral bulbar conjunctival injection without exudate; (C) rash; (D) erythema and oedema of the hands and feet in acute phase and periungual desquamation in subacute phase; and (E) cervical lymphadenopathy | Two or three principal clinical features or a positive echocardiogram | Kawasaki disease-like clinical features and any of the following causing initiation of volume expansion, vasoactive agents, or transfer to the intensive care unit: systolic hypotension based on age, or a decrease in systolic blood pressure from baseline by 20% or more, or clinical signs of poor perfusion |
| Exclusion | Other microbial cause of inflammation | Any other microbial cause | Other plausible alternative diagnoses | .. | .. | Other microbial cause |
| SARS-CoV-2 status | Positive RT-PCR, antigen test, or serology; or any contact with patients with COVID-19 | RT-PCR positive or negative | Positive RT-PCR, serology, or antigen test; or COVID-19 exposure within the past 4 weeks before symptom onset | .. | .. | .. |
MIS-C=multisystem inflammatory syndrome in children. PIMS-TS=paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2. SARS-CoV-2=severe acute respiratory syndrome coronavirus 2.
*
In the presence of four or more principal clinical features, particularly when redness and swelling of the hands and feet are present, the diagnosis of Kawasaki disease can be made with only 4 days of fever.