Table 2:

CDC criteria for multisystem inflammatory syndrome in adults and children with SARS-CoV-2 infection and Kawasaki disease2–4

CharacteristicMultisystem inflammatory syndrome in adultsMultisystem inflammatory syndrome in childrenKawasaki disease
Case definitionHospital admission of a patient aged ≥ 21 yr without evidence of severe respiratory illness and no alternative plausible diagnosis and involvement of 1 or more extrapulmonary organ systems:

  • Hypotension or shock

  • Cardiac dysfunction

  • Arterial or venous thromboembolism

  • Acute liver injury and laboratory evidence of acute inflammation

Patient aged < 21 yr with fevers > 38.0°C for ≥ 24 h, or report of subjective fever lasting ≥ 24 h with laboratory evidence of clinically severe illness requiring hospital admission with multisystem (≥ 2) organ involvement:

  • Cardiac

  • Renal

  • Respiratory

  • Hematologic

  • Gastrointestinal

  • Dermatologic

  • Neurologic

Complete Kawasaki disease:
Fevers ≥ 5 d
AND ≥ 4 principal clinical features

  • Extremity changes*

  • Rash†

  • Conjunctivitis‡

  • Oral changes§

  • Cervical lymphadenopathy (at least 1.5 cm in diameter, usually unilateral)

Suspected incomplete Kawasaki disease:
Fevers ≥ 5 d
AND
2–3 compatible clinical criteria, or infants with fevers ≥ 7 d without other explanation.
Supportive investigations and laboratory findingElevated CRP, ferritin, D dimer or IL-6Elevated CRP, ESR, fibrinogen, procalcitonin, D dimer, ferritin, lactate dehydrogenase or IL-6, elevated neutrophils, reduced lymphocytes and low albuminCRP ≥ 3.0 mg/dL
(or) ESR ≥ 40 mm/hr
AND
1) Positive echocardiogram: From AHA criteria,2 echocardiography is considered positive if any of 3 conditions are met:

  • Z score of left anterior descending coronary artery or right coronary artery ≥ 2.5; coronary artery aneurysm is observed; or ≥ 3 other suggestive features exist, including decreased left ventricular function, mitral regurgitation, pericardial effusion

  • or Z scores in left anterior descending coronary artery

  • or right coronary artery of 2–2.5

OR
2) ≥ 3 supportive laboratory findings (anemia for age, platelet count ≥ 450 000 after 7th day of fevers, albumin ≤ 3.0 g/dL, elevated alanine aminotransferase, leukocytes ≥ 15 000/mm3, or urine with ≥ 10 leukocyte/hpf)
SARS-CoV-2Positive for current or previous SARS-CoV-2 infection (nucleic acid, antigen, or antibody) during admission or in the previous 12 wkPositive for current or recent SARS-CoV-2 infection by RT-PCR, serology or antigen test, or exposure to a suspected or confirmed COVID-19 case within 4 wk before onset of symptomsNA

  • Note: AHA = American Heart Association, CDC = Centers for Disease Control and Prevention, CRP = C-reactive protein, ESR = erythrocyte sedimentation rate, hpf = high power field, IL-6 = interleukin 6, NA = not applicable, RT-PCR = reverse transcription–polymerase chain reaction.

  • ↵* Erythema and edema of the hands and feet in acute phase or periungual desquamation in subacute phase, or both.

  • ↵† Maculopapular, diffuse erythroderma or erythema multiforme-like.

  • ↵‡ Bilateral bulbar conjunctival injection without exudate.

  • ↵§ Erythema and cracking of lips, strawberry tongue, or erythema of oral and pharyngeal mucosa.