Kids and Coronavirus — Should We Be Worried?
Breaking Down a Recently Published Study on Multisystem Inflammatory Syndrome (MIS-C)
President Trump recently dismissed coronavirus cases in children, saying that they only represent a ‘tiny fraction’ of deaths. Meanwhile, local news stations around the country are reporting on a mysterious illness that is killing young children.
The juxtaposition between nonchalant dismissal and imminent danger is understandably dizzying. What is this disease everyone keeps talking about? How are children affected? How worried should you be?
The new, scary COVID-related disease at the center of the current controversy is Multisystem Inflammatory Syndrome (MIS-C), a rare but serious complication of COVID-19. Sorting through the deluge of information at our fingertips can be overwhelming. This is particularly true in medicine, which is plagued by bad science and anecdotal reports.
Here, I break down a credible study recently published in the New England Journal of Medicine that provides some insight into this new coronavirus-related illness. I’ll keep it simple, clarify some of the main takeaways, and pull in other studies to fill in the gaps. For those of you who are looking for the 20-second summary, feel free to skip to the ‘Main Takeaways’ section at the end of the article.
Who’s at risk for Multisystem Inflammatory Syndrome (MIS-C)?
The table below is a simplified version of the major demographic data reported by the study. Some important takeaways and clarifications:
- Children between ages 3 and 13 appear to be at the highest risk. This is notably older than children affected by Kawasaki’s disease, a similar acute febrile illness that affects children.
- The study doesn’t tell much about the role played by race/ethnicity. The utility of the demographic data is limited by both geographic factors, a narrow 3-month study window, and the large number of patients identified as “unknown.” While the percentage of Black and Hispanic children affected by multisystem inflammatory syndrome was higher than the U.S. population overall, it was similar to the reported percentage of Black and Hispanic children who have Covid-19. In other words, we should be concerned that there are ethnic and racial disparities, but we shouldn’t necessarily attribute those disparities to underlying biological differences.
- Healthy children are very much at risk. This is perhaps the most important demographic takeaway from the study and is consistent with other reports.
- Obesity is likely a significant risk factor for the development of Multisystem Inflammatory Syndrome. The authors of the study urged caution in using the data to interpret risk, particularly with respect to factors such as age, sex, and ethnicity. However, it is also true that obesity was a greater risk factor than all other risk factors combined.
- There is a delay between getting sick with COVID and developing Multisystem Inflammatory Syndrome. This finding has its limitations, which the authors of the study acknowledge. However, it is likely that, in most cases, between one week and one month will pass after a child gets sick with COVID before they develop Multisystem Inflammatory Syndrome. This is particularly important given that COVID symptoms will likely improve before the symptoms of Multisystem Inflammatory Syndrome begin.
How Serious is Multisystem Inflammatory Syndrome (MIS-C)?
Not surprisingly, the study tells us that Multisystem Inflammatory Syndrome is a very serious illness. Four out of every five children had to be admitted to an intensive care unit, and one out of every five children needed invasive mechanical ventilation.
While only 2% of patients died, the study only evaluated patients over a 3 month period and almost a third of all patients were still hospitalized when the study was completed.
As such, it is reasonable to assume that the mortality rate of Multisystem Inflammatory Syndrome is well above 2% and will remain so until we better understand the disease and how to treat it.
Multisystem Inflammatory Syndrome is not simply a disease of the lungs. In fact, at least 4 organ systems were involved in most cases. Below is a simplified table showing the most commonly involved organ systems. The effects on the cardiovascular system are particularly concerning. Almost half of all patients required medications to maintain blood pressure and coronary-artery aneurysms were identified in roughly one in ten children.
What causes Multisystem Inflammatory Syndrome (MIS-C)?
This study fits the current narrative that Multisystem Inflammatory Syndrome is a consequence of an overreaction of the immune system. The immune system’s ability to respond to and control disease is truly extraordinary.
However, if unchecked the response to disease can be worse than the disease itself. This study found extensive laboratory evidence of a runaway immune response. This is further supported by the delayed onset between initial infection and the development of Multisystem Inflammatory Syndrome.
Doctors are still figuring out how best to treat Multisystem Inflammatory Syndrome, but the current recommendations include provisions directed against controlling the underlying inflammatory process.
Some Caveats and Extras
Dismissing the severity of Coronavirus in children would be a mistake. However, it is also true that children are roughly 20 times less likely than adults to be hospitalized as a result of Coronavirus infection.
It is also important not to confuse Coronavirus infection with Multisystem Inflammatory Syndrome, which is a complication of Coronavirus infection. While Coronavirus poses less risk to children than older adults, all children that are affected by Multisystem Inflammatory Syndrome are very ill.
Additionally, Multisystem Inflammatory Syndrome, unlike Coronavirus, is not contagious. In fact, the study supports the general belief that Multisystem Inflammatory Syndrome occurs after the contagious stage of the disease.
The long-term effects of Multisystem Inflammatory syndrome are not known. Unchecked, inflammation often causes complications later in life, particularly for diseases that involve the cardiovascular system.
Given that Multisystem Inflammatory Syndrome is predominantly a cardiovascular disease, it is important to seek out treatment early if you suspect that your child is sick.
For a list of symptoms and what to do if you think your child is ill, check out the recommendations from the Centers for Disease Control.
Main Takeaways
- Children between age 3 and age 13 appear to be at the highest risk, particularly if they are obese.
- Don’t assume that your kid won’t get sick just because they are healthy, especially since the potential long-term effects of Multisystem Inflammatory Syndrome are still unknown.
- Most children will experience a week or more delay between initial COVID symptoms and the onset of Multisystem Inflammatory Syndrome.
- Don’t confuse Coronavirus with Multisystem Inflammatory Syndrome. They are two different illnesses that differ in their severity, risk profile, and treatment.
Our understanding of COVID-19 and its effects is constantly evolving. The preceding only provides a snapshot of a disease that is still very new and poorly understood.
The specifics are bound to change over time, and we should always approach data with skepticism, especially when it is based on a single study. For example, this study found that the average age was between 3 and 13, although both of the patients with Multisystem Inflammatory Syndrome that I saw on my pediatric rotation last week were over age 14.
The real danger posed by Multisystem Inflammatory Syndrome should not be overlooked. That said, Multisystem Inflammatory Syndrome is rare and overall Coronavirus poses less danger to children than to adults.
It is understandable to be worried about your loved ones in times of uncertainty.
My advice: be cautious, but don’t panic. In the words of the Roman philosopher Seneca, “We are more often frightened than hurt; and we suffer more from imagination than from reality.”
