A 10-year comparative study of factors for allergic asthma and/or rhinitis in two cross-sectional surveys.

Background: The allergenic relevance of the living environment changes over the last decades is largely unknown.

Objective: We aimed to compare the factors associated with asthma and/or rhinitis between 2008 and 2018.

Methods: We assessed two nationally representative cross-sectional datasets in 2008 and 2018. Within the rigorous protocol, questionnaire and serum IgE measurement were conducted in 2322 and 2353 patients with allergic asthma (A) and/or rhinitis (R) respectively. Multivariate logistic regression analysis was used to examine the effect of different factors on sensitization.

Results: The prevalence of sensitization increased in rhinitis alone (A-R+, 63% in 2008 vs. 67.7% in 2018, P = 0.039) and asthma with rhinitis (A+R+, 70.6% vs. 75.1%, P = 0.014). The common factors for sensitization were male sex, using mattress and air conditioner, family history of rhinitis, building age > 30 years, and meat consumption. Compared with 2008, secondhand smoke was an additional risk factor for A+R- (odds ratio [OR] 2.17, 95% confidence interval [CI] 1.18-7.01) and A+R+ (OR 1.72, 95%CI 1.03-3.14), and the odds of farmland or forest for pollen and mold sensitization were higher in 2018 (OR 3.61, 95%CI 2.79-4.66, and OR 1.86, 95%CI 1.34-2.58). Eating fish was inversely associated with A-R+ (OR 0.68, 95%CI 0.52-0.91, P < 0.01), while older age also showed an inverse relationship with sensitization. The OR of age 25-44 years was higher in 2018.

Conclusions: Repeated surveys showed variations in the factors affecting allergic asthma and/or rhinitis. The variable factors included age of 25-44 years, secondhand smoke, farmland, forest, and fish consumption.