Early-onset wheezing in preschool children: etiology, risk factors, and implications for asthma prevention

Purpose: This study aimed to examine the etiological factors and clinical characteristics of wheezing in preschool children presenting to the emergency department, focusing on environmental, viral, and demographic risk factors. Materials and Methods: A total of 199 children aged 27 days to 70 months (mean age 19.38 months) were included in this prospective study conducted from November 2017 to January 2019. Demographic, clinical, and environmental data were collected, and respiratory virus detection was performed using PCR tests. The modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire, administered to parents, assessed asthma susceptibility and potential wheezing triggers. Results: Wheezing was present in 97.5% of the patients at presentation. Respiratory viruses were identified in 67.3% of cases, with rhinovirus (33.5%) and RSV (25%) being the most frequent pathogens. Rhinovirus peaked in autumn, while RSV was more prevalent in spring. Early wheezing onset, male gender, and shorter breastfeeding duration (< six months) were associated with higher wheezing recurrence. Allergic comorbidities, including asthma and atopic dermatitis, were present in 8% of children. House dust and pollen were the primary environmental triggers. Conclusion: The study highlights the significant role of viral infections in preschool wheezing episodes and suggests preventive measures, such as influenza vaccination and reduced daycare attendance for children under three during peak viral seasons, to limit viral exposure.