ObjectivesProlonged symptoms after acute COVID-19 have been described in the pediatric population. Our objective was to know the prevalence of prolonged symptoms in children with confirmed SARS-CoV-2 infection, and to describe their clinical characteristics and possible risk factors.Patients & methodsMulticentre retrospective study carried by telephone questionnaire of all children under 18 years old diagnosed of symptomatic COVID-19, both hospitalized and outpatient attended in three hospitals in Spain between March and December 2020. Long-COVID was defined as the presence of symptoms longer than 12 weeks. A control group of children attended by other causes was also contacted and compared.Results451 children met criteria and agreed to participate; 370/451 (82%) presented mild outpatient infection, and 23 required admission in PICU (5.1%). The mean age was 5.9 years old (SD 5.3). A control group of 98 children was included.In 66 cases (14.6%) at least one symptom lasted longer than 12 weeks. Insomnia, concentration problems, apathy or sadness and anxiety were the longest (median >90 days). Age above 5 years (48/66; 72.7%, OR: 3, CI 95% (1.8-5)); admission (OR 3.9 CI 95% (2.2-6.8)), the need for PICU (OR 4.3 CI 95% (1.8-10.4)), and to have a relative with prolonged symptoms (OR 2.8 CI 95% (1.5-5.2)) were significantly associated with Long-COVID. When comparing with controls age above 5 years old, myalgia, asthenia, and loss of appetite were significantly associated with Long-COVID.ConclusionsOur study shows that children also suffer prolonged symptoms after COVID-19 infection, and require specific attention.

Aim We investigated prolonged symptoms in children after COVID‐19, including the clinical characteristics and risk factors. Methods This multicentre retrospective study focused on 451 children under 18 years old who were diagnosed with symptomatic COVID‐19 between 14 March and 31 December 2020. Persistent symptoms were analysed with a telephone questionnaire by the attending physicians from 1 August to 30 September 2021. A control group of 98 with no history of COVID‐19, who were treated for other reasons, was also included. Results Most (82.0%) of the cases had mild infections that required outpatient care and 5.1% were admitted to the paediatric intensive care unit (PICU). We found that 18.4% had symptoms that lasted 4–12 weeks. There were also 14.6% who were symptomatic for longer than 12 weeks and the odds risks were higher for children aged 5 years or more (OR 3.0), hospitalised (OR 3.9), admitted to the PICU (OR 4.3) and with relatives who were symptomatic for 12 weeks or more (OR 2.8). The controls had similar percentages of prolonged symptoms, despite having no history of COVID‐19, especially those who were older than 5 years. Conclusion This study confirmed that a worrying percentage of children had prolonged symptoms after COVID‐19.

The prevalence of asthma in children in Europe is an average of 10.3%. The role of asthma as a risk factor for COVID-19 in children is unknown. Our aim was to study the prevalence of asthma in children with SARS-CoV-2 infection and to compare them in hospitalized children and those with mild ambulatory symptoms. We conducted an observational retrospective study in 99 children (between 3- 17 years of age) with a confirmed SARS-CoV-2 infection between March and December 2020. The existence of a history of asthma was investigated using the validated ISAAC questionnaire and clinical data on COVID-19 were compiled. The median age was 10 years (IQR=13-5), and 60/99 (60.6%) patients had mild infections controlled as outpatient, while 39/99 (39.4%) required admission. The prevalence of asthma ─affirmative response to question 6 of the ISAAC questionnaire─ was 11.1% (11/99). The prevalence of asthma in children who required admission increased to 17.9% and to 21.4% in patients requiring PICU, while in outpatients children was 6.7% (p=0.079). We found a significant association between the use of salbutamol during the last year and the need for admission (23.1% in hospitalized patients vs 3.3% in outpatients; OR= 8.7, 95%CI 1.7-42.8). Likewise, budesonide treatment in the last year (17.9% vs 1.7%, OR= 12.9, 95%CI 1.5-109.5) was also a risk factor for admission. Therefore, a history of asthma was not a risk factor for SARS-CoV-2 infection in our series, but active asthma could be a risk factor for severity and need for hospitalization for COVID-19 in children