Severe COVID-19 infection in children. What are the symptoms of multisystem inflammatory disease?

Dr. Sandro Cantoni, Pediatrician. Updated: 20 September 2021

My child has a fever, is sick, has a stomach ache and is vomiting. What if he has COVID? I have heard of a serious form in children. What is it? How do I notice it?

I get this question a lot, partly because in the newspapers and media we hear about this serious infection, which fortunately is very rare. 

Usually the COVID-19 infection is mild in the child.

Often there are no symptoms, or a moderate infection with fever, cough, often diarrhea, which heals quickly. Sometimes, however, the illness can be significant and some times severe. 

As in the case of a condition called Multisystem Inflammatory Disease. 

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What is multisystem inflammatory disease? 

It is a significant, serious disease in which different parts of the body are inflamed, such as the heart, blood vessels, kidneys, intestines, and others. 

The cause is not known. What we do know is that children who have this disease have come in contact with the coronavirus, maybe even a few weeks before. 

That is, they have a positive swab, or antibodies are found, or they have been in close contact with a person with Covid-19

It is important to know the suspicious symptoms, to confirm the diagnosis quickly and admit the child, in most cases to the Intensive Care Unit.   

What are the symptoms that may lead you to suspect systemic inflammatory disease?

Fever for more than 24 hours plus one of the following symptoms: 



Belly pain

Skin rash

Redness and swelling of the lips or tongue

Pink eyes


Neck pain

Redness or swelling of the hands or feet

If your child has a fever and one or more of these symptoms, contact your pediatrician right away. 

When to go to the emergency room?

Call an ambulance or go to the emergency room if your child has the following severe symptoms: 

Doesn’t wake up or falls asleep often

Talks strangely, has a confusional state

Has a severe stomachache

Difficulty breathing

Chest pain

Has a blue, cyanotic face or lips. 

This disease is very rare, but prompt diagnosis is important. 


Whittaker E, Bamford A, Kenny J, et al. Clinical characteristics of 58 children with a pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2. JAMA 2020 June 8

Leora R. Feldstein e al, Multisystem Inflammatory Syndrome in U.S. Children and Adolescents. N Engl J Med 2020; 383:334-346

Anne H. Rowley. Multisystem Inflammatory Syndrome in Children and Kawasaki Disease: Two Different Illnesses with Overlapping Clinical Features. J Pediatr. 2020 Jun 22

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