Objective: This retrospective observational cohort study aimed to assess the real-life application of bronchial challenge test (BCT) in the management of preschool children presenting with atypical recurrent respiratory symptoms (ARRS). Methods: We included children, aged 0.5-6 years referred to a pediatric-pulmonology clinic, who underwent BCT using methacholine or adenosine between 2012-2018 due to ARRS including uncertain severity of airway hyperactivity. BCT was considered positive based on spirometry results and/or wheezing, desaturation, and tachypnea reactions. We collected data on demographics, BCT results, pre-BCT treatment, post-BCT treatment change and post-BCT symptoms control. The primary outcome measure was the change in treatment post-BCT (step-up or step-down). Secondary outcome included clinical improvement observed 3-6 months after BCT. Results: A total of 228 children (55% males) with a mean age of 4.2±0.6 years underwent BCT (52% adenosine-BCT, 48% methacholine-BCT). Children referred for methacholine were significantly younger compared to adenosine (3.6±1.2 vs. 4.2±1.2 years, P<0.01). Methacholine and adenosine BCTs were positive in 95% and 61%, respectively. Overall, changes in management were observed in 122(53.5%) children following BCT, with 83(36.4%) being stepped up and 37(17%) being stepped down. Significantly more children in the methacholine group were stepped up compared to the adenosine (46% vs 28%, p=0.004). During the follow-up assessment, we observed a clinical improvement in 119/162 (73.4%) of the children. Conclusion: This study demonstrates the importance of BCT in the management of preschool children presenting to pediatric pulmonary-units with ARRS. The change in treatment and subsequent clinical improvement observed, highlight the added-value of BCT in this populations.

Background: Since the outbreak of the Coronavirus disease 2019 (COVID-19) pandemic, there has been a decline in pediatric emergency department visits. Our aim was to assess the pattern of pediatric foreign body aspiration (FBA) during the first year of the COVID-19, in comparison to the prior years. Methods: In this retrospective multicenter study, we compared the number of children that presented with FBA during the COVID-19 year (March 1st, 2020 to February 28, 2021), to the annual average of the years 2016-2019. We also compared the lockdown periods to the post-lockdown periods and the percentage of missed FBA, proven FBA, and flexible bronchoscopy as the removal procedure. Results: 345 children with FBA from six centers were included, 276 in the pre-COVID-19 years (average 69 per year) and 69 in the COVID-19 year. There was no difference in the prevalence of FBA between the COVID-19 year and any of the prior four years. Examining the lockdown effect, the monthly incidence of FBA dropped from a pre-COVID-19 average of 5.75 cases to 5.1 cases during lockdown periods and increased to 6.3 cases in post-lockdown periods. No difference in the percentage of missed FB or proven FB was observed. There was a significant rise in the usage of flexible bronchoscopy as the removal procedure (Average of 15.4% vs 30.4%, p=0.001) Conclusion: There was no difference in the prevalence of FBA during the COVID-19 year. However, there were fewer cases during lockdown periods, compared to post-lockdown periods, presumably related to better parental supervision.