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.1-3
  • 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).1-3
  • Some patients develop cardiac dysfunction (e.g., decreased left ventricular function) and coronary artery dilatation or aneurysm.1,2,4
  • 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.7,8
  • Other severe neurologic manifestations may include encephalopathy, stroke, demyelination, and fulminant cerebral edema, although this is rare.7,8
  • 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 studies 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. See How to Protect Yourself and Others for information on staying up to date with COVID-19 vaccinations.
  • ÐÇ¿ÕÓéÀÖ¹ÙÍø and FDA  that MIS-C occurring after COVID-19 vaccination be reported to the .
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  • 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. doi:10.1093/cid/ciac471
  • 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. doi:10.1093/cid/ciab1007
  • 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. doi:10.1016/S0140-6736(20)31094-1
  • 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. doi:10.1161/CIRCULATIONAHA.120.048360
  • 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. doi:10.1016/j.epsc.2021.101838
  • 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. doi:10.1093/jpids/piab050
  • 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;doi:10.1001/jamaneurol.2022.3881
  • 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. doi:10.1001/jamaneurol.2021.0504