Clinical Overview of Multisystem Inflammatory Syndrome in Children

At a glance

  • MIS-C may begin weeks after a child is infected with SARS-CoV-2. The child may have been infected from an asymptomatic contact, and, in some cases, the child and their caregivers may not even know they had been infected.
  • COVID-19 vaccination is effective at reducing the risk of MIS-C.
Three health care providers discussing interventions

Signs and symptoms

  • Patients with MIS-C usually present with fever and some combination of abdominal pain, vomiting, diarrhea, skin rash, and mucocutaneous lesions (i.e., conjunctivitis). In severe cases, children can present with hypotension and shock.123
  • Patients with MIS-C have elevated laboratory markers of inflammation (e.g., C-reactive protein, ferritin); many have laboratory markers indicating damage to the heart (e.g., elevated troponin), and many have low platelet or absolute lymphocyte counts (thrombocytopenia and lymphopenia, respectively).123
  • Some patients develop cardiac dysfunction (e.g., decreased left ventricular function) and coronary artery dilatation or aneurysm.124
  • Gastrointestinal inflammation can manifest as abdominal pain, vomiting, and diarrhea; children may have signs and symptoms similar to those of acute appendicitis.5
  • Neck pain has also been described, sometimes with development of phlegmon on radiographic imaging.6
  • Children with MIS-C can also have neurologic involvement which is usually transient and presents as headache or altered mental status. 78
  • Other severe neurologic manifestations may include encephalopathy, stroke, demyelination, and fulminant cerebral edema, although this is rare.78
  • Not all children will have the same signs and symptoms, and some children may have symptoms not listed here. MIS-C may begin weeks after a child is infected with SARS-CoV-2. The child may have been infected from an asymptomatic contact, and, in some cases, the child and their caregivers may not even know they had been infected.

Reducing risk

MIS-C and vaccination

  • Multiple studies91011 have found that COVID-19 vaccination is effective at reducing the risk of MIS-C, with finding that two doses of Pfizer-BioNTech COVID-19 vaccine had a greater than 90% estimated effectiveness at preventing MIS-C. 12 See How to Protect Yourself and Others for information on staying up to date with COVID-19 vaccinations.
  • 13 CDC and FDA  that MIS-C occurring after COVID-19 vaccination be reported to the .
Keep Reading: How to Protect Yourself and Others

Resources

Print
Content Source:
National Center for Immunization and Respiratory Diseases; Coronavirus and Other Respiratory Viruses Division (CORVD)
  1. Miller AD, Yousaf AR, Bornstein E, et al. Multisystem Inflammatory Syndrome in Children During Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Delta and Omicron Variant Circulation-United States, July 2021-January 2022. Clin Infect Dis. Oct 3 2022;75(Supplement_2):S303-S307.
  2. Miller AD, Zambrano LD, Yousaf AR, et al. Multisystem Inflammatory Syndrome in Children-United States, February 2020-July 2021. Clin Infect Dis. Aug 24 2022;75(1):e1165-e1175.
  3. Riphagen S, Gomez X, Gonzalez-Martinez C, Wilkinson N, Theocharis P. Hyperinflammatory shock in children during COVID-19 pandemic. Lancet. May 23 2020;395(10237):1607-1608.
  4. Belhadjer Z, Meot M, Bajolle F, et al. Acute Heart Failure in Multisystem Inflammatory Syndrome in Children in the Context of Global SARS-CoV-2 Pandemic. Circulation. Aug 4 2020;142(5):429-436..
  5. Valitutti F, Verde A, Pepe A, et al. Multisystem inflammatory syndrome in children. An emerging clinical challenge for pediatric surgeons in the COVID 19 era. J Pediatr Surg Case Rep. Jun 2021;69:101838.
  6. Jenkins E, Sherry W, Smith AGC, et al. Retropharyngeal Edema and Neck Pain in Multisystem Inflammatory Syndrome in Children (MIS-c). J Pediatric Infect Dis Soc. Oct 27 2021;10(9):922-925.
  7. LaRovere KL, Poussaint TY, Young CC, et al. Changes in Distribution of Severe Neurologic Involvement in US Pediatric Inpatients With COVID-19 or Multisystem Inflammatory Syndrome in Children in 2021 vs 2020. JAMA Neurol. Nov 7 2022;
  8. LaRovere KL, Riggs BJ, Poussaint TY, et al. Neurologic Involvement in Children and Adolescents Hospitalized in the United States for COVID-19 or Multisystem Inflammatory Syndrome. JAMA Neurol. May 1 2021;78(5):536-547.
  9. Villacis-Nunez DS, Jones K, Jabbar A, et al. Short-term Outcomes of Corticosteroid Monotherapy in Multisystem Inflammatory Syndrome in Children. JAMA Pediatric. Jun 1 2022;176(6):576-584.
  10. Schwartz N, Ratzon R, Hazan I, et al. Multisystemic inflammatory syndrome in children and the BNT162b2 vaccine: a nationwide cohort study. Eur J Pediatr. 2024 Aug;183(8):3319-3326.
  11. Nygaard U, Holm M, Hartling UB, et al. Incidence and clinical phenotype of multisystem inflammatory syndrome in children after infection with the SARS-CoV-2 delta variant by vaccination status: a Danish nationwide prospective cohort study. Lancet Child Adolesc Health. Jul 2022;6(7):459-465.
  12. Zambrano LD, Newhams MM, Olson SM, et al. Overcoming COVID-19 Investigators. BNT162b2 mRNA Vaccination Against Coronavirus Disease 2019 is Associated With a Decreased Likelihood of Multisystem Inflammatory Syndrome in Children Aged 5-18 Years-United States, July 2021 - April 2022. Clin Infect Dis. 2023 Feb 8;76(3):e90-e100.
  13. Yousaf AR, Cortese MM, Taylor AW, et al. MIS-C Investigation Authorship Group. Reported cases of multisystem inflammatory syndrome in children aged 12-20 years in the USA who received a COVID-19 vaccine, December, 2020, through August, 2021: a surveillance investigation. Lancet Child Adolesc Health. 2022 May;6(5):303-312.