Study shows differences between children and adolescents in Long COVID

More than a dozen long-COVID symptoms overlapped between school-age children and adolescents. However, a large longitudinal observational study of children in the United States found differences.

In models adjusted for sex, race and ethnicity, 14 persistent symptoms in children ages 6 to 11 and adolescents ages 12 to 17 were more common in those with a history of COVID-19 than in those without a history, with four distinct symptom phenotypes in school-age children and three in adolescents, reported Dr. Rachel Gross of the NYU Grossman School of Medicine in New York City and colleagues in JAMA.

Researchers identified 18 persistent symptoms that were more common in school-age children, including headaches (57%), memory or concentration problems (44%), sleep problems (44%), and stomach pain (43%). In adolescents, 17 symptoms were more common, including daytime fatigue/sleepiness or low energy (80%), body, muscle, or joint pain (60%), headaches (55%), and memory or concentration problems (47%).

In school-age children, four clusters included a group affecting multiple body systems: headaches, musculoskeletal pain, and low energy/sleepiness; sleep disturbances and problems with memory/concentration; and gastrointestinal symptoms. In adolescents, three clusters included multiple body symptoms, musculoskeletal pain and low energy/sleepiness; and changes or loss in sense of smell or taste.

A Long COVID Research Index was created for each age group from the symptom combinations most strongly associated with infection history, Gross and his team found, adding that these indices correlated with poorer overall health and quality of life.

“Currently, the majority of long-COVID research focuses on adults,” said Gross MedPage Today“This lack of focus on the pediatric population has led to major gaps in our understanding of how long COVID affects children – making this study a critical advance in long COVID research in children.”

“In examining different symptom groups across a wide range of childhood ages, RECOVER [trial] The researchers found that while many of the long-COVID symptoms were similar, they were still distinct from each other,” she said. “For example, we found four different symptom clusters in school-age children and three in adolescents, suggesting that there may be multiple types of long-COVID in children that may change as they grow and develop.”

“This tells us that a one-size-fits-all approach to diagnosing children with long Covid would probably not be effective,” she added. “Instead, it is likely that future screening or diagnostic tools – as well as treatments – will need to be tailored to specific age groups.”

In an editorial accompanying the study, Suchitra Rao, MBBS, MSCS, of the University of Colorado School of Medicine and Children's Hospital Colorado in Aurora, noted that along with the adult RECOVER study published in 2023, “the publications underscore the importance of evaluating chronic conditions such as [long COVID] across the entire spectrum of life, as there were clear differences in the presentation among children, adolescents and adults.”

She noted that headaches are common in children but less common in adolescents and adults. In addition, “a cluster of gastrointestinal symptoms occurred only in school-age children, while gastrointestinal symptoms in adults were more likely to occur in association with other symptoms,” she wrote.

Gross said this study is “a first step toward a future tool for detecting long COVID in children and adolescents, and it is expected that this study will change as researchers learn more about it.”

“Therefore, it is not currently intended for clinical use,” she noted. “Instead, we hope this lays the groundwork for future long-COVID research in children. We also hope these findings will help families, clinicians and healthcare teams by raising awareness of long-COVID and demonstrating that children can develop long-COVID and that their symptoms may be different from those in adults.”

For this study, participants were recruited from more than 60 healthcare and community settings across the United States between March 2022 and December 2023. Their caregivers completed a survey assessing 89 persistent symptoms across nine domains. The median time between initial infection and survey was 506 days for school-age children and 556 days for adolescents.

Persistent symptoms are defined as those that have lasted longer than four weeks, have occurred or worsened since the beginning of the pandemic, and were present at the time the survey was conducted (at least 90 days after infection).

Gross and his team studied 751 school-age children with a previous SARS-CoV-2 infection and 147 without previous infection. The average age was 8.6 years, 49% were girls, 60% were white, 34% were Hispanic/Latin/Spanish, and 11% were black or African American.

This included 3,109 adolescents with a previous SARS-CoV-2 infection and 1,360 without previous infection. The average age was 14.8 years, 48% were girls, 73% were white, 21% were Hispanic/Latin/Spanish, and 13% were black or African American.

Overall, 45% of infected and 33% of uninfected school-age children and 39% of infected and 27% of uninfected adolescents reported having at least one persistent symptom. In addition, 26 symptoms in infected children and 18 symptoms in infected adolescents remained persistent in at least 5% of participants.

Of the 751 infected children, 20 percent reached the Long COVID Research Index threshold, as did 14 percent of infected adolescents.

Limitations included that children may have had COVID for a long time without reaching the index threshold. In addition, some participants may have been misclassified in the infected and uninfected groups. Recall bias was also possible because symptoms were reported by caregivers.