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Rare Inflammatory Reaction to COVID in Children

Pia Boben Fenimore, M.D.


Pediatricians across the world have recently started to alert epidemiologists to cases of a new disease preliminarily named Pediatric Multi-Symptom Inflammatory Syndrome (PMIS) which is likely related to the COVID 19 pandemic.  Parents need to be aware of this syndrome, however, they do not need to panic.  As with most things COVID related, there are still a lot of unanswered questions about PMIS and how it affects our children, so here is a collation of the information that has been reported both in popular media and medical sources so far.


PMIS is a constellation of symptoms including fever for 4-5 days, swollen lymph nodes, and rash.   It is thought to be an inflammatory reaction to the virus and may appear for several weeks after initial infection.  Other symptoms which may or may not be present include stomach pain, red eyes, diarrhea, and swollen hands and feet.   Unlike traditional COVID disease, respiratory symptoms, such as cough or shortness of breath, do not seem to be common in this presentation.


This syndrome can progress to serious disease including blood pressure instability, toxic shock, and heart failure.  The cascade of inflammation affects the blood vessels and coronary arteries and can cause decreased circulation to critical organs.  It is not clear if these children will suffer from long term consequences of this syndrome.  It is expected that they will need extended follow up with a pediatric cardiologist.


While statistics are very new and may not be completely accurate, the age range for PMIS is wide; infant to age 18, but most common in 5-10-year old children.  Many of the children diagnosed with this syndrome have tested positive for COVID however, some have tested negative so there may be other viral or genetic links that are not understood.


As we begin to learn more about this virus, we understand that it binds to and affects the ACE2 cellular receptors in the body.   These receptors can be found in almost every part of the body however adults have high volume of these receptors in the airway and lung tissues.  In children, it is thought that these receptors are more spread out, which may be why they get less respiratory disease, but also may be why we are seeing a multi symptom syndrome develop in some children.  A genetic variant found in some of the patients with PMIS also may prove to be the answer to why some people get this severe form of disease.


Despite many needing intensive care support,  most of the pediatric patients with PMIS have fully recovered.  Treatments which have been shown to be useful include intravenous immunoglobulins, and steroids.


This type of syndrome is not new to pediatricians, as it is like Kawasaki’s Disease which was first documented in 1967 in Japan.  According to the CDC there are about 5000 cases of Kawasaki’s in the United States per year.   PMIS is certainly similar, but not exactly like Kawasaki’s, mostly differing in the way it affects the vascular system as well as being more common in older children.  Pediatricians are  familiar with the idea of viral infections presenting in unusual ways in children, fortunately this familiarity often means early diagnosis and effective treatment.


PMIS is exceedingly rare.  To date there have been less than 200 cases worldwide.  These reports do not change the fact that most COVID 19 infections in children remain very mild without long term effects.  Based on current information available, it does not seem that parents need to be overly worried about this new syndrome.


If your child has had fever for greater than 3 days, or fever and a rash, or fever and abdominal pain then a healthcare provider should see them.  This recommendation is the same as it has always been but is now even more important with the potential presence of PMIS.  Health care providers have been advised to begin reporting and tracking these types of cases so there will likely be more information forthcoming.  In the meantime, parents should focus on keeping their children and themselves physically and emotionally healthy while practicing social distancing.   Please reach out to your pediatric health care provider with any concerns.  We are here for you as always.