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 August 1, 2022, the New York State Department of Health has investigated and confirmed 820 cases of MIS-C and 3 deaths attributed to MIS-C in New York children (under 21 years old). 

Of the children confirmed as MIS-C cases, 94 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 August 1, 2022)

Race and Ethnicity of Cases (as of August 1, 2022)

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 has clinical, general/virologic laboratory, and epidemiological criteria:

• An individual aged <21 years presenting with fever¹, laboratory evidence of inflammation², and evidence of clinically severe illness, with multisystem (>2) organ involvement (cardiac, renal, respiratory, hematologic, gastrointestinal, dermatologic or neurological); AND
• Who is hospitalized, evaluated in the Emergency Department, seen in an observation, admitted inpatient or transferred from another facility; AND
• No alternative plausible diagnoses; AND
• Positive for current or recent acute SARS-CoV-2 infection by RT-PCR, serology, or antigen test; OR exposure to a suspected or confirmed COVID-19 case within the 4 weeks prior to the onset of symptoms; or received a COVID-19 vaccine in the prior 6 weeks.

Confirmed cases of MIS-C must meet all three Clinical and one or more of the General/Virologic Laboratory/Epidemiological criteria.

Clinical Criteria

1. An individual aged < 21 years presenting with
   • Fever¹
   • Laboratory evidence of inflammation²
   • Multisystem (>2) organ involvement (cardiac, renal, respiratory, hematologic, gastrointestinal, dermatologic, or neurological);
   • RT-PCR
   • Serology
   • Antigen test
                                AND
2. Hospitalization
   • Evaluated in the Emergency Department
   • Seen in observation
   • Admitted inpatient
   • Transferred to or received from another facility
                                AND
3. No alternative plausible diagnoses

AND

General /Virologic Laboratory/Epidemiological Criteria

1. Within the 3 months prior to illness onset, the individual tested positive for SARS-CoV-2 by
   • RT-PCR
   • Serology
   • Antigen test
                                              OR
2. Exposure to a suspected or confirmed COVID-19 case within the 4 weeks prior to the onset of symptoms
                                              OR
3. Received any doses of COVID-19 vaccine in the prior 6 weeks.

Additional comments:

• Some individuals may fulfill full or partial criteria for Kawasaki Disease but should be reported as MIS-C if they meet the case definition for MIS-C.
• Consider MIS-C in any pediatric death with evidence of recent COVID-19 infection or vaccination.

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

1. Fever >38.0°C for ≥24 hours, or report of subjective fever lasting ≥24 hours
2. Including, but not limited to, one or more of the following: an elevated C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), fibrinogen, procalcitonin, d-dimer, ferritin, lactic acid dehydrogenase (LDH), or interleukin 6 (IL-6), elevated neutrophils, reduced lymphocytes and low albumin

Additional information about MIS-C can be found of the CDC website.

Study in the New England Journal of Medicine: The Department of Health published a study of children with the Multisystem Inflammatory Syndrome in the New England Journal of Medicine on June 29, 2020.