In children, symptoms of long COVID vary by age group, scientists building research index find

The older adult group consisted of 4,469 younger adults, of whom 3,109 (70%) were infected and 1,360 were uninfected. The mean age was 14.8 years, 48% were female, 73% were white, 21% were Hispanic, and 13% were black.

“Most of the studies characterizing the symptoms of long COVID have focused on adults, which may lead to the misconception that long COVID in children is rare or that symptoms are similar to those in adults,” David Goff, MD, PhD, director of the division of cardiovascular sciences at NIH's National Heart, Lung, and Blood Institute, said in the NIH paper. News Release.

“Symptoms vary from child to child and present in different patterns, so without proper characterization of symptoms across the lifespan, it is difficult to know how to optimize care for affected children and young people,” said Goff, who was not an author of the study.

Symptom clusters lead to poorer health

In total, Forty-five percent of infected school-age children and 33% of uninfected children, as well as 39% of infected adolescents and 27% of uninfected adolescents, reported at least one persistent symptom, also known as a post-acute sequelae of SARS-CoV-2 infection (PASC). Twenty-six symptoms in infected younger children and 18 symptoms in infected adolescents persisted in at least 5% of participants.

The symptom clusters most related to infection formed the basis of the PASC study index for each age group and correlated with poorer overall health and quality of life: in younger adults, pain, neurocognitive symptoms, and gastrointestinal symptoms dominated the index, while abnormal smell or taste, pain, and fatigue were more prominent in adolescents.

The PASC index threshold was set at 5.5 for the younger group and 5.0 for the older group. Twenty percent of infected school-age children and 4% of uninfected children, and 14% of infected adolescents and 3% of uninfected met or exceeded this threshold. This proportion was higher in participants infected before the emergence of the SARS-CoV-2 omicron variant than after its emergence (21% vs. 14% in the younger group and 17% vs. 7% in the older group).

The most common long-term symptoms among school-age children with possible PASC that also contributed to the study index were headaches (57%), memory, concentration, and sleep problems (44%), and stomach pain (43%). The most common symptoms not included in the index were pain (51%), daytime sleepiness (49%), and anxiety (47%).

“Similar but distinct”

The four symptom clusters seen in younger children were (1) high incidence of many symptoms, (2) headaches (95%), pain (60%), and daytime sleepiness (52%), (3) sleep problems (64%), and poor memory or concentration (62%), and (4) stomach pain (100%) and nausea or vomiting (61%).

Three clusters were identified among adolescents: (1) a high prevalence of many symptoms, (2) daytime sleepiness (89%) and pain (87%), and (3) problems with smell or taste (100%) and relatively low prevalence of other symptoms.

Symptom patterns were similar but distinct between school-age children and adolescents, highlighting the importance of characterizing PASC separately in different age groups.

Among adolescents with possible PASC, the most common persistent symptoms contributing to the index were daytime sleepiness (80%), pain (60%), headache (55%), and memory and concentration problems (47%). Among symptoms not contributing to the index, the most common were sleep problems (47%), anxiety (47%), and depression (38%).

“Symptom patterns were similar yet distinct between school-age children and adolescents, highlighting the importance of characterizing PASC separately in different age groups,” the researchers wrote.

NYU Langone Health News Release“Our study indicator is a first step toward a tool that may be used in the future to identify long COVID in children and adolescents, a group that has not been widely studied, but it is subject to change and expansion as we learn more and is not intended to be used as a clinical tool at this time,” said Rachel Gross, MD, a professor in the system's departments of pediatrics and public health and lead author of the paper.

Four years later, much remains unknown

Related editorialSuchitra Rao, MS, of the University of Colorado School of Medicine, said a possible limitation of the study was that there were no baseline measurements to determine pre-infection status, so they couldn't determine whether quality of life scores reflected chronic disease rather than PASC symptoms in people who joined later in the study.

“Four years after the first reports of Long COVID, much remains to be learned about the trajectory and strategies for prevention and management, particularly for children,” she wrote.

“The general public and the scientific community, especially those who continue to live with symptoms on a daily basis, eagerly await the results of further investigations from RECOVER-Pediatrics, which will help shed more light on long COVID in children.”