Early life wheeze and risk factors for subsequent asthma -- a revisit at age 7 years in the GEWAC-cohort

Background: One third of all toddlers are in need of medical care because of acute wheeze and many of these children continue to have asthma at school age. Our aim was to assess the prevalence of asthma among the children in GEWAC at age 7 years. And investigate why some children continue to have recurrent wheeze and asthma at school age. Methods: The study included 156 cases with acute wheeze, recruited from the paediatric emergency ward, Astrid Lindgren’s Children’s Hospital, Stockholm, Sweden and 102 age-matched controls. Cases attended a follow-up visit after 3 months, after one year and at age 7 years. The protocol included questionnaires, ACT, FENO, nasopharyngeal virus samples, blood sampling for cell count, Vitamin D and IgE to food and airborne allergens. Results: A total of 70.8 % of the cases and 1.9 % of the controls had asthma at age 7 (p<0.001). Acute wheeze caused by Rhinovirus (RV) infection at inclusion was more common among cases with asthma at age 7 compared to cases without asthma (p=0.011). When adjusting for other viruses, RV remained significantly associated with asthma at age 7 (OR 3.8 95% CI 1.4-10.5). Cases with asthma at age 7 had been admitted to hospital more often (p=0.024) and spent more days admitted (p=0.01) during the year following inclusion. Conclusion: Rhinovirus induced acute wheeze is a risk factor for asthma by age 7. Cases with asthma at age 7 were hospitalized more frequently and needed more inpatient time during the year after inclusion.