The COVID-19 pandemic has caused a great deal of worry and concern for the health of our loved ones. It is fortunate that cases of COVID-19 are less severe in children, who, if they are infected, often show mild symptoms or no symptoms. Doctors are currently learning more about Pediatric Multisystem Inflammatory Syndrome (PMIS), a rare, but serious inflammatory condition. It can be seen in a small number of children who either had COVID-19 or were exposed to it. Doctors are learning more about the possible connection between PMIS and COVID-19. Vandana Madhavan, MD, MPH, an infectious disease specialist, and Kateri McGuinness, RN, MSN, PNP, a pediatric nurse practitioner in Pediatric Cardiology at MassGeneral Hospital for Children (MGHfC), answer common questions surrounding PMIS.

What Is Pediatric Multisystem Inflammatory Syndrome (PMIS)?

Pediatric Multisystem Inflammatory Syndrome (PMIS) is a very rare, but serious inflammatory condition that affects children. Recently, cases of PMIS have been seen in children who tested positive for COVID-19, showing evidence of either a past or recent infection. However, not all children with PMIS have had positive COVID-19 testing and doctors are still learning about a possible link between the two illnesses.

What Are the Symptoms of PMIS?

Mild symptoms of PMIS include fever, cough, sore throat and a rash. It can also cause swelling of the hands, feet and lymph nodes. In more severe cases, PMIS can also affect blood pressure, the heart and the kidneys.

Symptoms of PMIS may not appear until several weeks after the initial infection. In some cases, families may not know their child had COVID-19 until they show symptoms of PMIS. In general, it is important to remember that symptoms of COVID-19 tend to be milder or do not appear as often in children.

Some Symptoms of PMIS Are Similar to Symptoms of Kawasaki Disease. Are PMIS and Kawasaki Disease the Same?

No, PMIS and Kawasaki disease are different conditions, although the symptoms can appear similar. Inflammation in children with PMIS also appears to be more severe. The good news, though, is that even though children may become more ill with PMIS than Kawasaki disease, most children recover.

Both PMIS and Kawasaki disease cause persistent fever, rash, redness of the eyes and swelling of the hands, feet and lymph nodes. Unlike Kawasaki disease, children with PMIS may also have belly pain, vomiting or diarrhea. Some children with severe PMIS may also have blood clots, kidney injury or inflammation of the heart.

PMIS and Kawasaki disease tend to affect children of different ages. PMIS is more common in young children and teens, whereas Kawasaki disease is more likely to affect children under age 5.

What Causes PMIS?

The cause of PMIS is not known, but doctors think it is related to a COVID-19 infection. The body’s immune system may somehow cause severe inflammation in some children who are more likely to develop PMIS, based on their genetics. Doctors are starting to look at genetic and immune factors that could explain what puts some children at risk.

Is PMIS Contagious?

From what we know of PMIS, it seems to be a post-infectious complication of COVID-19, an illness that typically occurs up to several weeks after an initial infection and is therefore not contagious. Even if a child develops PMIS, tests positive for COVID-19 and might be infectious to others, it is important to remember that a very small percentage of children with COVID-19 develop PMIS.

How Do Doctors Diagnose PMIS?

To diagnose PMIS, doctors obtain a detailed history, do a physical exam and blood tests. They may also do an echocardiogram (ultrasound) of the heart and other studies.

Does MGHfC Treat Children with PMIS?

Yes. MGHfC providers are here and available to evaluate and treat children with PMIS virtually, in the clinic and if they are admitted to the hospital. MGHfC has a team of specialists to develop guidelines for diagnosis and treatment of PMIS. The team includes providers from Pediatric Cardiology, Pediatric Infectious Disease, Pediatric Rheumatology and Pediatric Critical Care. The team may also speak with pediatricians by video or phone calls.

What Are the Best Recommendations to Treat PMIS?

We are still learning about the spectrum of illness and symptoms in PMIS associated with COVID-19. Not all children need medication. Mild symptoms, like fever, cough or sore throat, can be treated at home with fluids and fever reducers, such as acetaminophen.

Hospitalized children with more severe symptoms of PMIS may be treated with medications to help their blood pressure, heart function or to treat blood clots. They may also need different types of corticosteroids or anti-inflammatory medications. If children have PMIS and COVID-19, they may also need blood products and/or antiviral therapy.

What Should Parents Do If Their Children Have the Symptoms?

Parents with concerns about their child’s symptoms should call their pediatrician’s office to discuss what the next steps should be. Some children will need to have blood work or other tests done, and a few children may need to be admitted to the hospital.

Do You Think PMIS Would Become a Big Problem During the COVID-19 Pandemic?

The number of children with PMIS is increasing in multiple countries, such as the United Kingdom, Italy and the United States, several weeks after the COVID-19 infection peak. However, it is important to remember that the number of children who have PMIS remains low compared to the overall number of COVID-19 infections. The number of children who have very severe complications remains even lower. We will continue to learn more over the coming weeks.

What Is Massachusetts Doing to Help?

MGHfC providers are here and available to evaluate and treat children with PMIS virtually, in the clinic and if they are admitted to the hospital.

The Massachusetts Department of Health is currently collecting data on reported cases of PMIS throughout Massachusetts. Visit the Centers for Disease Control and Prevention (CDC) and the Massachusetts Department of Public Health for information on how providers define and report cases of PMIS.

MassGeneral Hospital for Children and Massachusetts General Hospital do not endorse any of the brands listed on this handout. This webpage is intended to provide health information so that you can be better informed. It is not a substitute for medical advice and should not be used to treatment of any medical conditions.