A large study conducted in Denmark found that kids who recently had COVID-19 experienced symptoms of long COVID more often than similar kids who didn’t have a COVID-19 diagnosis. But, long COVID among children seems less common than it is among adults.
Researchers asked thousands of parents about their kids’ symptoms that lasted more than 2 months including stomach ache, chest pain, headache, fatigue, joint pain, memory loss, and more. Though these symptoms were somewhat more common in kids who had COVID-19, they were not unusual in kids who didn’t have COVID-19.
WHO defines post-COVID-19 condition (also called long COVID or PASC) among adults as “persistent or fluctuating symptoms with an influence on daily functioning following SARS-CoV-2 infection for at least 2 months that cannot be explained by an alternative diagnosis.”
Reports of post-COVID-19 condition in kids are easy to find. But so far, there have been few high-quality studies with a control group that might tell us how common it is.
In a study published recently in the Lancet, Danish researchers asked thousands of parents to report on their children’s’ long-COVID-like symptoms like stomach ache, fatigue, dizziness, trouble concentrating, and more. They considered these symptoms to be “long-lasting” if they persisted for two months or more.
The researchers compared the frequency of these long-lasting symptoms between kids who had a known COVID-19 case and kids who didn’t.
In kids between ages 0 and 3, 40% who had COVID-19 reported at least one symptom lasting more than 2 months. 28% of kids who did not have COVID-19 had one of these symptoms. So you might think of this as 12% higher than “baseline” or a 78% increase over baseline.
In kids between 4 and 11, 38% of kids who had COVID-19 had at least one of these long-lasting symptoms, compared to 34% of kids who did not have COVID-19. That’s 4% higher or a 23% increase over baseline.
And In the oldest age group in the study, 46% of 12- to 14-year-olds who had COVID-19 reported one or more long-lasting symptom, compared to 41% of those with no known COVID-19 infection. That’s 5% higher or a 21% increase over baseline.
This was a large case-controlled study. It offers some strong evidence that COVID-19 infection in kids can lead to long-lasting symptoms, similar to in adults–but at lower rates.
One limitation is that the “case” parents may have been more likely to respond if their child was suffering with one of these symptoms. Parents of every kid in Denmark who tested positive for COVID-19 during a 6-month window (yes all of them) were invited to participate, but only 1 in 5 of their parents responded to the survey. Another limitation is that the study was conducted before the big Delta-Omicron surge.
This study adds to our growing understanding of long COVID in children. Another international study estimated that perhaps 3-5% of kids will have long COVID symptoms. In several studies, including this Danish study, certain symptoms (difficulty concentrating, muscle pain for example) are actually higher in the kids who *didn’t* have COVID-19.
Bottom line: long COVID in kids is still largely an unknown quantity, but there’s growing evidence that it doesn’t affect as many kids as adults. Talk to your pediatrician if your child is experiencing symptoms like the ones listed here after they’ve recovered from COVID-19.
Here are some of our previous posts about this topic: