Table 1

Three case definitions of paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-21–3

Country (organisation)Case definition
  • Children and adolescents 0–19 years of age with fever >3 days

AND two of the following:
(a) rash or bilateral non-purulent conjunctivitis or muco-cutaneous inflammation signs;
(b) hypotension or shock;
(c) features of myocardial dysfunction, pericarditis, valvulitis or coronary abnormalities;
(d) evidence of coagulopathy;
(e) acute gastrointestinal problems (diarrhoea, vomiting or abdominal pain)
  • Elevated markers of inflammation such as ESR, CRP 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

  • An individual aged <21 years presenting with fever, laboratory evidence of inflammation and evidence of clinically severe illness requiring hospitalisation, with multisystem (≥2) organ involvement

  • No alternative plausible diagnoses

  • 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

  • A child presenting with persistent fever, inflammation (neutrophilia, elevated CRP and lymphopenia) and evidence of single or multi-organ dysfunction (shock, cardiac, respiratory, renal, gastrointestinal or neurological disorder) with additional features. This may include children fulfilling full or partial criteria for Kawasaki disease

  • Exclusion of any other microbial cause, including bacterial sepsis, staphylococcal or streptococcal shock syndromes, infections associated with myocarditis such as enterovirus (waiting for results of these investigations should not delay seeking expert advice)

  • SARS-CoV-2 PCR testing may be positive or negative

  • CDC, Centers for Disease Prevention and Control; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; RCPCH, Royal College of Paediatrics and Child Health; RT-PCR, reverse transcription polymerase chain reaction.