Clinical Treatment of Multisystem Inflammatory Syndrome in Children

Treatment timeline

During hospitalization

• Depending on the child's illness severity and manifestations, multiple specialists (e.g., cardiologists, critical care specialists, hematologists, infectious disease specialists, and rheumatologists) may participate in management.
• It is important to evaluate patients with suspected MIS for alternative diagnoses, particularly as MIS clinical manifestations overlap with those of other etiologies. Testing to evaluate for other potential diagnoses should be directed by patient signs or symptoms.
• Alternate diagnoses to consider include:
  • Acute viral infection (e.g., SARS-CoV-2, influenza virus, adenovirus)
  • Acute viral infection myocarditis (e.g., influenza virus, enteroviruses)
  • Kawasaki disease
  • Rickettsial disease (e.g., typhus)

• Laboratory testing for inflammatory markers (e.g., C-reactive protein) should be performed and may be repeated over the course of hospitalization to monitor response to treatment. Other laboratory markers may be followed depending on MIS-C organ involvement (e.g., cardiac enzymes, liver enzymes, platelets, absolute lymphocyte count).
• Children and adults with MIS and evidence of cardiac involvement (i.e., elevated cardiac enzymes or shock) will likely have at least one echocardiogram performed during their hospitalization and may have repeat echocardiograms depending on findings.
• Treatment generally involves the use of anti-inflammatory drugs. Anti-inflammatory measures have included the frequent use of intravenous immunoglobulin (IVIG) and steroid therapy.1
• Prolonged duration of outpatient steroids should be avoided.2 The use of other anti-inflammatory medications (e.g., anakinra) and the use of anti-coagulation treatments have been variable and data are limited regarding their benefit.
• Aspirin has commonly been used because of concerns for coronary artery involvement, and antibiotics are routinely used to treat potential sepsis while awaiting bacterial cultures. Thrombotic prophylaxis is often used given the hypercoagulable state typically associated with MIS-C.

After hospitalization

• Evaluation and testing after hospitalization are based on the presentation and clinical course of each patient with MIS.
• Cardiology follow-up with repeat echocardiogram is generally recommended for patients with MIS cardiac manifestations.
• Exercise, sports, and strenuous activity are generally limited for children with MIS cardiac manifestations until cleared by a cardiologist.
• Follow-up with the patient's primary care provider is important. A conversation between the patient, their guardian(s), and the clinical team or a specialist should occur to assist with decisions about COVID-19 vaccination after MIS.

Long-term outcomes

• Most MIS-C patients have had good outcomes with no significant complications 1 year after diagnosis. Fewer adults with MIS (also known as MIS-A) have been reported, and longer-term complications in adult populations have not been well-characterized.
• Studies evaluating the long-term effects of MIS-C are ongoing.
• The limited data that are available show that, for most patients, inflammatory markers and abnormal echocardiogram findings will normalize within 4 weeks after hospitalization.
• Most signs and symptoms resolve by 6 months; signs and symptoms persisting at 6 months have included muscular fatigue, abnormalities on neurologic exam, anxiety, and emotional difficulties.
• Patients who experience persistent signs or symptoms can learn more about the long-term effects of COVID-19 on CDC's website.

Keep in mind

Resources

• American Academy of Pediatrics Multisystem Inflammatory Syndrome in Children (MIS-C) Interim Guidance 
• American College of Rheumatology Clinical Guidance for Multisystem Inflammatory Syndrome in Children Associated With SARS–CoV-2 and Hyperinflammation in Pediatric COVID-19: Version 3