TY - JOUR T1 - Asthma symptoms in pediatric patients: Differences throughout the seasons JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - p1130 AU - Ellen Koster AU - Jan Raaijmakers AU - Susanne Vijverberg AU - Anke-Hilse Maitland-van der Zee Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/p1130.abstract N2 - Background: Seasonal variation in asthma has been widely recognized. The aim of this study was to describe seasonal patterns of asthma symptoms and medication use in a cohort of pediatric asthma medication users and to study determinants of seasonal childhood asthma.Methods: For this study, 602 children participating in the PACMAN (Pharmacogenetics of Asthma medication in Children: Medication with Anti-inflammatory effects)-cohort were included. Parents were asked about their child's respiratory symptoms and rescue medication use over the past year.Results: There was a decline in asthma symptoms and medication use during the summer period and a peak occurred from autumn to spring. The prevalence of wheeze ranged from 32% in summer to 56% in autumn. The prevalence of respiratory symptoms and medication use was significantly lower during summer (p<0.0001). Oral steroid and antibiotic use and strong parental necessity beliefs were associated with uncontrolled asthma, regardless of seasonality. Allergic rhinitis was associated with an increased risk of uncontrolled asthma during spring (RR: 1.3 95%CI: 1.1-1.6) and summer (RR: 1.2 95%CI: 1.0-1.4). Eczema was associated with a higher risk of uncontrolled asthma during autumn (RR: 1.2 95%CI: 1.0-1.4) and winter (RR: 1.2 95%CI: 1.0-1.4).Conclusions: We showed seasonal patterns in asthma symptoms and medication use. We showed associations between allergic rhinitis and asthma control during spring/summer and eczema was associated with uncontrolled asthma during autumn/winter. Seasonality in asthma morbidity and health care use is most likely associated with atopic constitution and viral infections, which are common during fall, winter and spring. ER -