Table 2.

Definition of childhood inflammatory illnesses associated with SARS-CoV-2

MIS-C temporally associated with SARS-CoV-2	1. A child presenting with persistent fever, inflammation (neutrophilia, elevated CRP and lymphopenia) and evidence of single or multiorgan dysfunction (shock, cardiac, respiratory, renal, gastrointestinal, or neurological disorder) with additional features. This may include children meeting full or partial criteria for Kawasaki disease 2. 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) 3. SARS-CoV-2 PCR testing may be positive or negative
Typical Kawasaki disease, temporally associated with SARS-CoV-2	1. Classical criteria for Kawasaki disease 2. Evidence of SARS-CoV-2 infection or exposure 3. SARS-CoV-2 PCR may be positive or negative, and SARS-CoV-2 antibodies positive or negative
Febrile inflammatory syndrome, temporally associated with SARS-CoV-2	1. Febrile children with inflammatory blood markers (raised CRP, neutrophilia, lymphopenia, elevated D-dimers, ferritin), in whom other infectious or inflammatory causes cannot be identified 2. SARS-CoV-2 may be positive or negative by PCR and antibody

CRP C-reactive protein, MIS-C multisystem inflammatory syndrome in children, PCR polymerase chain reaction, SARS-CoV-2 severe acute respiratory syndrome coronavirus 2