New Condition Affecting Children, Related to COVID-19

In May of 2020, the CDC issued a national health advisory for a newly emerging potential complication of COVID-19 in children and young adults called multisystem inflammatory syndrome in children (MIS-C). Case reports from around the world document otherwise-healthy children presenting with cardiovascular shock, fever, and whole-body inflammation. Some symptoms appear similar to two other conditions, Kawasaki disease and toxic shock syndrome, with inflammation in the blood vessels of the body and heart complications. However, unlike Kawasaki disease, which typically affects children under the age of 5 years, this new illness appears in older children and adolescents, with an average age of 8 to 9 years. 

MIS-C Is Rare but Serious

Early reports of COVID-19 in children show a relatively mild form of the disease, with infants being at the highest risk of severe complications from an infection. However, as the SARS-CoV-2 virus spread globally, doctors began reporting cases of older children who were otherwise healthy with high levels of inflammation and low blood pressure that didn’t respond to fluid therapy. Many of these children were testing positive for either active COVID-19 or previous infection with SARS-CoV-2. The CDC has termed this new illness multisystem inflammatory syndrome in children (MIS-C), but it is also commonly called pediatric inflammatory multisystem syndrome (PIMS).

For children with MIS-C, symptoms can vary from one child to another and can involve any combination of fever lasting more than 24 hours; stomach pain; vomiting; diarrhea; rash; red and bloodshot eyes; extreme fatigue; confusion; trouble breathing; or pressure in the chest. If any of these symptoms are present, seek medical attention immediately. The doctor will assess the symptoms and issue laboratory tests to look for signs of inflammation and dysfunction of one or more organs, such as the heart or kidneys.

Hospitalization Is Common, Necessary

Most children with MIS-C will require treatment in the hospital, with a smaller percentage requiring treatment in pediatric intensive care. While in the hospital, the treatment focus is on reducing the symptoms while also managing the inflammation. Depending on the symptoms and the child’s condition, treatment may include anti-inflammatory medications such as corticosteroids, immunomodulators like IV immunoglobulin, and anticoagulants like aspirin to reduce the risk of blood clots. In some cases, medications used to increase blood pressure, called vasopressors, will be given to maintain adequate blood flow. Treatment with a ventilator or oxygen may be needed to ensure appropriate oxygen levels are maintained. With monitoring and treatment, most children will fully recover and return home. Rarely, children have died as a result of MIS-C.

Linked to Overactive Immune Response

Scientists are still investigating the exact cause of the disease and how it affects children in the short and long term. Early theories suggest that the cause of MIS-C is an overactive immune response to the SARS-CoV-2 virus or even the body reacting to the antibodies created in response to infection with the virus. The overactive immune response leads to the general inflammation seen in the heart, blood vessels, eyes, kidney, digestive system, and brain of children with MIS-C. The term “cytokine storm” is used to describe this excessive or uncontrolled release of proinflammatory cytokines by the body in response to an immune trigger. MIS-C seems to develop approximately 2 to 4 weeks after infection with COVID-19.

The condition is extremely rare, and most children only have very mild symptoms related to infection with SARS-CoV-2. Some, but not all, children suspected of MIS-C have tested positive for an active COVID-19 infection. Most children diagnosed have a positive antibody test indicating a recent infection with SARS-CoV-2. Early case studies demonstrate a higher proportion of disease presenting in Black and Hispanic children and those of South Asian descent.

If you are concerned about MIS-C, or have additional questions, reach out to your pediatrician or another healthcare professional for more information.

The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.