Multisystem Inflammatory Syndrome in Children (MIS-C)

MIS-C is a rare condition that sometimes occurs in children who have had COVID-19 infection. Symptoms of MIS-C typically develop two or more weeks following infection with COVID-19 and involves inflammation of different parts of the body, such as the heart, lungs, kidneys, brain, skin, eyes, or gastrointestinal system. What causes some children to develop MIS-C is not known. MIS-C can be serious or even deadly, but most children recover with medical care.

As of October 27, 2023, the New York State Department of Health has investigated and confirmed 935 cases of MIS-C and 4 deaths attributed to MIS-C in New York children (under 21 years old). 

Of the children confirmed as MIS-C cases, 93 percent tested positive for COVID-19 either by diagnostic tests (PCR or antigen), antibody tests or both.

As of 10/15/21, only confirmed MIS-C cases are being reported.

Age of Cases (as of October 27, 2023)

Race and Ethnicity of Cases (as of October 27, 2023)

Though most children who get COVID-19 experience only mild symptoms, some children experience severe illness after an apparent recovery from COVID-19 infection. Symptoms of MIS-C may occur two or more weeks after acute COVID-19 illness.

Should your child develop any of the following symptoms following COVID-19 illness, you should seek immediate care for your child from your child’s healthcare provider:

• Prolonged fever (more than 24 hours)
• Bloodshot eyes
• Skin Rash
• Stomach Pain
• Diarrhea
• Vomiting
• Difficulty feeding (infants) or is too sick to drink fluids

Should your child develop any of the following severe symptoms, you should seek emergency medical care when the child has:

• Change in skin color - becoming pale, patchy and/or blue
• Trouble breathing or is breathing very quickly
• Racing heart or chest pain
• Decreased amount or frequency of urine
• Confusion, not acting right, or won’t wake up or stay awake

Early recognition by pediatricians and referral to a specialist including to critical care are essential.

MIS-C Case Definition

The MIS-C case definition includes clinical, general/virologic laboratory, and epidemiological criteria.

• Age: Age <21 years
• Fever: Subjective or documented fever (≥38.0°C) Note: fever no longer needs to exceed 24 hours
• Illness Severity: Illness with clinical severity requiring hospitalization or resulting in death
• Alternative Diagnosis: A more likely alternative diagnosis is not present*
• Laboratory markers of inflammation: C-reactive protein ≥3.0 mg/dL (30 mg/L)

Organ System Involvement (2 or more)**

Cardiac

• Left ventricular ejection fraction <55%
• Coronary artery dilatation, aneurysm, or ectasia
• Troponin elevated above laboratory normal range or indicated as elevated in a clinical note

Shock

• Clinician diagnosis documented in medical records.

Hematologic

• Thrombocytopenia (platelet count <150,000 cells/μL)
• Lymphopenia (absolute lymphocyte count [ALC] <1,000 cells/μL)

Gastrointestinal

• Abdominal pain
• Vomiting
• Diarrhea

Dermatologic/Mucocutaneous

• Rash
• Inflammation of the oral mucosa
• Conjunctivitis or conjunctival injection
• Extremity findings
   

Laboratory Testing Criteria or Epidemiologic Linkage Criteria (1 or more)

Laboratory Testing

• Positive viral test (i.e., NAAT/PCR or antigen) up to 60 days prior to or during hospitalization, or in post-mortem specimen***
• Detection of SARS-CoV-2 specific antibodies associated with current illness^

Epidemiologic Linkage

• Close contact with a confirmed or probable case of COVID-19 disease in the 60 days prior to hospitalization

Death Certificate

• Death certificate lists MIS-C as an underlying cause of death or a significant condition contributing to death‡
   

Additional Information

• Information for Healthcare Providers about Multisystem Inflammatory Syndrome in Children (MIS-C) - CDC
• Multisystem Inflammatory Syndrome in Children in New York State – The New England Journal of Medicine

Clinicians with questions can contact the NYSDOH Bureau of Communicable Disease Control by email at [email protected] or by phone at 518-473-4439 during business hours or 1-866-881-2809 evenings, weekends, and holidays.
 

Notes

*Kawasaki Disease (KD) may be an acceptable alternative diagnosis. If a final diagnosis of KD is made, these cases should NOT be reported to MIS-C surveillance.

**Renal, respiratory, and neurologic involvement were previously case defining, but are no longer included in the current case definition.

***Positive molecular or antigen results from self-administered testing meet laboratory criteria.

^Detection of anti-nucleocapsid antibody is specific to a SARS-CoV-2 infection, while anti-spike protein antibody may be a result of COVID-19 vaccination or SARS-CoV-2 infection.

‡Consider MIS-C in any pediatric death with evidence of recent COVID-19 infection or vaccination.