Allergic rhinitis and asthma: A large cross-sectional study in the United Arab Emirates

Background: Studies on comorbidity of allergic rhinitis (AR) and asthma have been carried out in developed countries; however, data from countries in development transition are lacking. Methods: In a randomly selected, age-stratified cohort of adolescent school children and their caretakers in the United Arab Emirates (UAE), comorbidity of AR and asthma was calculated using multinomial regression to determine independent risk factors. Results: A total of 6,543 subjects were included in the study; the median age was 30 years (range 8-93), and 52% were males. The standardized prevalence of concomitant asthma and AR was 7.3%. AR subjects had a 3-fold increased risk of asthma compared to subjects without AR (23.8 and 7.5%, respectively). Immigrants had a significantly lower prevalence of comorbidity of AR and asthma [adjusted odds ratio (OR) 0.53, 95% confidence interval (CI) 0.33-0.85] compared to UAE nationals, while greater age carried a lower risk (adjusted OR 0.58, 95% CI 0.44-0.78), but a family history of both AR (adjusted OR 3.03, 95% CI 2.31-3.98) and asthma (adjusted OR 4.65, 95% CI 3.53-6.12) was strongly associated with the co-occurrence of these 2 conditions, while gender and education were not. Asthma patients with AR had more severe symptoms than those without, i.e. 'dry cough at night' in 65 versus 36%, β-mimeticum use in 42 versus 30%, and steroid use in 25 versus 13%, respectively. Conclusion: Comorbidity of asthma and AR in the UAE is high, with a prevalence of 7.3%. Both the underlying reasons and possibilities for better prevention now need to be focused on in future research.