Asthma with allergic comorbidities in adolescence is associated with bronchial responsiveness and airways inflammation
The study was performed within ORAACLE (the Oslo Research Group of Asthma and Allergy in Childhood; the Lung and Environment), a member of GA2LEN (Global Asthma and Allergy European Network), and MeDALL (Mechanisms of the Development of ALLergy), a collaborative project conducted within the European Union under the Health Cooperation Work Programme of the 7th Framework programme (grant agreement No. 261357).
Childhood asthma frequently has allergic comorbidities. However, there is limited knowledge of the longitudinal development of asthma comorbidites and their association to bronchial hyper-responsiveness (BHR) and airway inflammation markers. We therefore aimed to assess the association between childhood asthma with allergic comorbidities and BHR and fractional exhaled nitric oxide (FENO) and the impact of gender on these associations.
Based on data from 550 adolescents in the prospective birth cohort ‘Environment and Childhood Asthma’ study, asthma was defined for the three time periods 0–2, 2–10 and 10–16 years of age, using recurrent bronchial obstruction (rBO) 0–2 years of age as a proxy for early asthma. Asthma comorbidities included atopic dermatitis (AD) and allergic rhinitis (AR) from 10 to 16 years. At age 16 years BHR, assessed by metacholine bronchial challenge, and airway inflammation, assessed by FENO, were compared between the groups of asthma with or without the two comorbidities, to a reference group with no never asthma, and subsequently stratified by gender.
Boys with asthma and AR, regardless of AD had significantly more severe BHR and higher FENO than the other asthma phenotypes. Almost half of the children remained in the asthma and AR category from 10 to 16 years, the entire difference being determined by new incident cases from 10 to 16 years.
Asthma phenotypes characterized by allergic comorbidities and AR in particular appears closely associated with BHR and FENO, especially among boys.