What you need to know about Multisystem Inflammatory Syndrome in Children (MIS-C)

First pediatric death in Wisconsin

On Feb. 18, 2022, the Wisconsin Department of Health Services (DHS) reported the first death related to Multisystem Inflammatory Syndrome in Children (MIS-C) in Wisconsin. That child’s family is in our thoughts and has our deepest sympathy. Nobody should have to endure the loss of a child.

Children’s Wisconsin reminds the community that MIS-C is rare, but can be a result of COVID-19. All families should continue to practice the four W's – wash your hands, watch your distance, wear your mask, and work (or go to school) only when well. Finally, getting vaccinated when eligible and the booster when appropriate remains the best way to protect yourself and those around you.

Background

From the earliest days of the COVID-19 pandemic, one of the main understandings was that it didn’t affect healthy kids as seriously as adults. While that still remains true, in early May 2020 reports from New York and Los Angeles have talked about a “mysterious illness” that has shown up in some kids who have been exposed to the COVID-19 virus. Shortly after, the Centers for Disease Control and Prevention (CDC) issued a health alert as well.

This broad collection of symptoms are officially known as Multisystem Inflammatory Syndrome in Children (MIS-C). Some of these patients have been found to have inflammation of many organs including the heart and enlargement of the coronary blood vessels. They can present with many different symptoms including: a persistent high fever, swelling of the hands and feet, rash, and red eyes and tongue.

In most of these cases, these patients tested positive for COVID-19 antibodies (as opposed to testing positive for the actual virus). That means the child doesn’t currently have COVID-19, but did some weeks or months earlier and their body’s immune system fought it off.

In other words, MIS-C is not being caused by an active infection. Rather, it’s the result of their body’s immune response. For some reason, their immune systems are having this general inflammatory response weeks later. Fortunately, while MIS-C is a potential risk for any child following a COVID-19 exposure, there does not appear to be a greater risk for children with underlying health conditions, including heart disease.

MIS-C vs. Kawasaki

In the beginning, a lot of media reports have been connecting MIS-C with another disorder known as Kawasaki disease. It’s important to note that while similar, MIS-C and Kawasaki are not the same.

Kawasaki disease is a rare condition, affecting about 25 per every 100,000 kids in the country. It primarily affects kids under the age of 5 and its cause is not known.

It is generally rare but being the only hospital in the region dedicated to the care of kids, we do see it on a regular basis. We sometimes see a higher incidence in certain seasons and this is the time we typically see Kawasaki disease.

The primary symptom of Kawasaki is a high fever, typically greater than 102, for more than five days. Additionally, to receive a diagnosis of Kawasaki, a patient must have four out of the five following symptoms:

• Rash
  
  
• Red eyes
  
  
• Redness in palms and soles of the feet
  
  
• Changes to the lining of their nose and mouth (the mucous membrane)
  
  
• Enlarged lymph nodes

If left untreated, Kawasaki can lead to swelling of the heart and blood vessels, including the coronary arteries that supply blood to the heart muscle. That can have serious long-term health effects. However, while Kawasaki disease can be serious, if it’s caught early it is very often treatable with IV antibodies, high-dose aspirin and steroids.

While Kawasaki and MIS-C share similar symptoms, MIS-C results from a COVID-19 exposure. This means there is a correlation of a rise of MIS-C cases following a spike of COVID-19 cases in the community.

There is still much to be understood about MIS-C, but so far the CDC has reported the following:

• As of Feb. 18, 2022, there have been more than 6,850 cases and 59 deaths attributed to MIS-C.
  
  
• Cases have been reported in children under 1 year old up to 20 years old, but most cases occur between ages 5 and 13.
  
  
• 59 percent of reported cases have occurred in children who are Latino or Black.
  
  
• More than half (60 percent) of reported cases were male.

What we’ve seen at Children’s Wisconsin

At Children's Wisconsin, the majority of cases we've seen have had cardiac involvement, meaning the heart muscle or the coronary arteries are affected. In these cases, the child is admitted to our Pediatric Intensive Care Unit (PICU) for observation and care. The great news is that so far, the majority of kids have been getting better with treatment and there have been no indications of long-term complications. The treatment plan developed at Children’s Wisconsin has shown success in managing any cardiac risks and has been shared with other centers to better understand and follow our protocols.

The team has shared its findings with the Wisconsin DHS and has been approached by the CDC to join a small group of hospitals that have developed best practices in the identification and care of MIS-C.

Looking forward

Just like COVID-19, it will take some time for the medical community to fully understand MIS-C and its long-term impact. Of course, with more information and more data, the task becomes more achievable. That’s why Children’s Wisconsin has signed onto the Long-Term Outcomes after the Multisystem Inflammatory Syndrome In Children (MUSIC) study, a multi-center study that includes more than 30 leading medical centers from across the United States and Canada. The study is supported by the Pediatric Heart Network and funded by the National Institutes of Health. Together, centers will share long-term data on enrolled MIS-C participants to better understand any potential risks.

When to seek care

Now and always, we are available for parents — virtually and in-person — if they have any concerns about COVID-19 or MIS-C. Prolonged fever, rash, red eyes, abdominal pain — if a parent is seeing any of these symptoms, that would warrant calling a pediatrician at any time.

If parents are concerned, they should contact their child’s pediatrician by phone, MyChart message, schedule an appointment or they can talk to a pediatric care provider through our Online Urgent Care video visits.