MIS-C (Multisystem Inflammatory Syndrome in Children)
Content reviewed against published CDC, AAP, NIH guidelines
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MIS-C is a rare but serious condition where different body parts become inflamed, including the heart, lungs, kidneys, brain, skin, eyes, or gastrointestinal organs. It typically occurs 2-6 weeks after a SARS-CoV-2 (COVID-19) infection, even if the child was asymptomatic during the initial infection. It shares features with Kawasaki disease and toxic shock syndrome but is a distinct entity.
Key takeaways
- MIS-C is a rare but serious condition where different body parts become inflamed, including the heart, lungs, kidneys, brain, skin, eyes, or gastrointestinal organs.
- Duration: Hospital stay averages 5-7 days; ICU care needed in approximately 50-80% of cases. Most children recover fully within 4-6 weeks. Cardiac follow-up with echocardiograms continues for months. Long-term outcomes are still being studied.
- Go to ER if: Persistent high fever with abdominal pain and vomiting
- A vaccine or immunization is available
Symptoms
How It Presents by Age
0-4 years
Less common in this age group. When it occurs, may present more like Kawasaki disease with fever, rash, conjunctivitis, and mucous membrane changes. Coronary artery involvement possible.
Risk level: Moderate
5-11 years
More common presentation. Prominent GI symptoms (abdominal pain, vomiting, diarrhea) alongside fever. May have cardiac involvement. Rash and conjunctivitis common.
Risk level: Moderate to high
12-18 years
Can present with more cardiac involvement and shock. Older children may have more prominent cardiac dysfunction and may require vasopressor support. GI symptoms remain prominent.
Risk level: High (more severe cardiac involvement)
18-21 years
Rare but recognized in young adults. Presentation similar to adolescents with significant cardiac and GI involvement.
Risk level: Moderate to high
Treatment
IVIG (Intravenous Immunoglobulin)
Standard first-line therapy, typically 2 g/kg given over 12-24 hours. Reduces inflammation and cardiac complications. Similar to Kawasaki disease treatment protocol.
Corticosteroids
IV methylprednisolone (1-2 mg/kg/day) given alongside IVIG. Studies show combination therapy may be superior to IVIG alone for MIS-C. Tapered over 2-3 weeks.
Anticoagulation
Low-dose aspirin for all patients. Therapeutic anticoagulation (enoxaparin) for patients with coronary artery aneurysms, severe cardiac dysfunction, or documented thrombosis.
Cardiac support
Inotropes and vasopressors for cardiac dysfunction and shock. Close monitoring in ICU with serial echocardiograms and cardiac biomarkers.
Biologic therapy
Anakinra (IL-1 receptor antagonist) or infliximab (anti-TNF) for refractory cases not responding to IVIG and steroids.
Supportive care
IV fluids (careful with volume if cardiac dysfunction), respiratory support, electrolyte management, and nutritional support.
Home Care
- MIS-C requires hospital treatment — there are no home remedies for the acute phase
- After hospital discharge, follow all medication instructions (including steroid taper)
- Keep all follow-up cardiology appointments
- Restrict physical activity until cleared by cardiology
- Monitor for any return of fever or new symptoms
- Discuss timing of COVID-19 vaccination with your pediatrician
- Report any chest pain, shortness of breath, or exercise intolerance promptly
When to Worry
Go to the ER if:
- Persistent high fever with abdominal pain and vomiting
- Signs of shock — rapid heart rate, cold extremities, lethargy
- Chest pain or difficulty breathing with fever
- Child is confused, limp, or difficult to arouse
- Severe abdominal pain mimicking appendicitis
- Child looks very unwell with multi-system symptoms (fever + rash + red eyes + GI symptoms)
- Non-blanching rash with fever
Call your doctor if:
- Fever lasting more than 24 hours after known or suspected COVID-19 exposure
- New rash with persistent fever
- Abdominal pain with fever, especially if recent COVID-19 exposure
- Red eyes with fever and other systemic symptoms
- Child who had COVID-19 weeks ago and now has persistent fever
Keep an eye on:
- Fever lasting more than 24 hours in a child who had COVID-19 in the past 2-6 weeks
- Severe abdominal pain with fever
- Combination of fever + rash + red eyes + GI symptoms
- Child appears very unwell with persistent fever
- Chest pain or difficulty breathing with fever
- Child becomes confused or extremely lethargic
Prevention
- COVID-19 vaccination reduces the risk of MIS-C significantly
- Vaccination is recommended for all eligible children
- General COVID-19 prevention measures (hand hygiene, avoiding sick contacts)
- Early recognition of symptoms allows for prompt treatment
- Be aware of MIS-C if your child had COVID-19 in the previous 2-6 weeks
Contagion & Incubation
Incubation
Typically develops 2-6 weeks after SARS-CoV-2 infection or exposure. The child may have had no symptoms during the initial COVID-19 infection.
Contagious for
Not contagious. MIS-C is an immune-mediated inflammatory condition, not an active infection.
Duration
Hospital stay averages 5-7 days; ICU care needed in approximately 50-80% of cases. Most children recover fully within 4-6 weeks. Cardiac follow-up with echocardiograms continues for months. Long-term outcomes are still being studied.
Frequently asked questions
How long does mis-c (multisystem inflammatory syndrome in children) last?
How does multisystem inflammatory syndrome in children (mis-c) spread?
When should I take my baby to the ER?
Can multisystem inflammatory syndrome in children (mis-c) be prevented?
When can my child return to daycare?
Sources
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources
Related Illnesses
Bottom line
MIS-C (Multisystem Inflammatory Syndrome in Children) is treatable with appropriate medical care. Seek emergency care if persistent high fever with abdominal pain and vomiting.
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.