Table 2.

Clinical characteristics of KD, SARS-CoV-2 infection, and MIS-C

Characteristics of SARS-CoV-2-associated diseases
Parameters analyzed	SARS-CoV-2 infection	KD	MIS-C
Pathology	Viral infection	Pediatric vasculitis	Hyperinflammatory syndrome
Mean age of disease onset	Any	< 5	6–11
Gender predisposition (M:F ratio)	1:1	1.5:1	1.5:1
Demographics	Worldwide	Japan	Hispanic and non-Hispanic Black in the USA
Genetic predisposition	ACE deletion (D) polymorphism	Genetic polymorphism of ITPKC	Inborn errors of immunity
Diagnostic procedure	PCR, antigen test, antibodies (reactive IgG or IgM to SARS-Cov-2)	No single specific diagnostic test	No single specific diagnostic test
Main diagnostic markers	Reactive IgG or IgM to SARS-CoV-2	IL-18, IL-21, Elevated N-terminal pro-BNP	IL-18, IgG against S protein, elevated N-terminal pro-BNP, lymphopenia
Similar symptoms	Fever, cough, fatigue	Fever (> 5 days if left untreated), lymphadenopathy, mucocutaneous findings, conjunctivitis, rash	Fever, lymphadenopathy, mucocutaneous symptoms, conjunctivitis, rash
Characteristic symptoms	Respiratory complications	Erythema and edema of extremities	Gastrointestinal findings
Pathognomonic symptoms	N/A	Strawberry tongue	N/A
Major complications	MIS-C	Coronary artery aneurysm	Myocardial dysfunction
Treatment	Often self-limited	IVIG, acetylsalicylic acid	IVIG, GCS

SARS-CoV-2 severe acute respiratory syndrome coronavirus 2, KD Kawasaki disease, MIS-C multisystem inflammatory syndrome in children, ITPKC inositol-triphosphate three kinase C, ACE angiotensin converting enzyme, PCR polymerase chain reaction, IL-18 interleukin 18, IL-21 interleukin 21, pro-BNP pro-B-type natriuretic peptide, IgG immunoglobulin G, IVIG intravenous immunoglobulin, GCS glucocorticosteroids, N/A not applicable, USA United States of America