Natural course of acute COVID‐19 among healthy children in a tertiary hospital.

Background: Previous studies have reported the clinical and epidemiological characteristics of children with coronavirus disease 2019 (COVID‐19) in a cross‐sectional fashion; however, the natural course of each symptom based on a daily basis during the acute phase has not yet been clarified. This retrospective study aimed to describe the natural course of COVID‐19 in children according to dominant variants. Methods: We conducted our study on symptomatic children with COVID‐19 who were hospitalized at the National Center for Child Health and Development, in Japan. We excluded patients who were observed for less than 9 days and those with underlying disease, COVID‐19 vaccination, coinfection, complications, or therapeutic intervention. We collected the data on each participant's age at admission, sex, medical history, observation period, hospitalization period, SARS‐CoV‐2 test results, and 10 daily symptoms in the first 9 days from the illness onset. Results: Eventually, 115 children were included in this study. The prevalence of fever during the omicron era declined more rapidly over time than that during the pre‐omicron era. The prevalence of cough and rhinorrhea did not decline during the observation period, and these clinical manifestations were more common during the pre‐omicron era at any point. The prevalence of dysgeusia and/or dysosmia steadily increased over time in the pre‐omicron era. This study demonstrated that the prevalence of some symptoms differed not only at the onset but also over time during the acute phase. Conclusion: Details of the natural clinical course of children with COVID‐19 help primary care physicians to manage these patients. [ABSTRACT FROM AUTHOR]