Giovita A. Piccillo

Cigarette smoking is associated with a greater risk of incident asthma in allergic rhinitis

BACKGROUND Asthma and rhinitis are often comorbid conditions, and several studies have suggested that rhinitis often precedes asthma. Sensitization to allergen has been shown to be one of the strongest determinants of incident asthma, but little is known about the effects of cigarette smoking among individuals with allergic rhinitis. OBJECTIVE We sought to evaluate the importance of cigarette smoking as an additional risk factor for incident asthma in a cohort of hospital-referred nonasthmatic adult subjects with allergic rhinitis. METHODS The study population selected at baseline was invited for a follow-up visit 10 years later to check for possible asthma features. Categories of smokers, exsmokers, and never smokers were used in the analyses together with pack-years to calculate the level of cumulative exposure. RESULTS Complete data were available from 325 patients. Smoking was significantly related to the risk of incident asthma, with the odds ratio (OR) being 2.67 (95% CI, 1.70-4.19) for univariate and 2.98 (95% CI, 1.81-4.92) for multivariate analyses. A clear dose-response association for exposure to tobacco and risk of new-onset asthma was observed in the multivariate analyses: those with 1 to 10 pack-years had an OR of 2.05 (95% CI, 0.99-4.27), those with 11 to 20 pack years had an OR of 3.71 (95% CI, 1.77-7.78), and those with 21 or more pack-years had an OR of 5.05 (95% CI, 1.93-13.20) compared with never smokers. CONCLUSIONS The current findings support the hypothesis that cigarette smoking is an important independent risk factor for the development of new asthma cases in adults with allergic rhinitis.

Greater risk of incident asthma cases in adults with Allergic Rhinitis and Effect of Allergen Immunotherapy: A Retrospective Cohort Study

Asthma and rhinitis are often co-morbid conditions. As rhinitis often precedes asthma it is possible that effective treatment of allergic rhinitis may reduce asthma progression.The aim of our study is to investigate history of allergic rhinitis as a risk factor for asthma and the potential effect of allergen immunotherapy in attenuating the incidence of asthma.Hospital-referred non-asthmatic adults, aged 18–40 years between 1990 and 1991, were retrospectively followed up until January and April 2000. At the end of follow up, available subjects were clinically examined for asthma diagnosis and history of allergen specific immunotherapy, second-hand smoking and the presence of pets in the household. A total of 436 non-asthmatic adults (332 subjects with allergic rhinitis and 104 with no allergic rhinitis nor history of atopy) were available for final analyses.The highest OR (odds ratio) associated with a diagnosis of asthma at the end of follow-up was for the diagnosis of allergic rhinitis at baseline (OR, 7.8; 95%CI, 3.1–20.0 in the model containing the covariates of rhinitis diagnosis, sex, second-hand smoke exposure, presence of pets at home, family history of allergic disorders, sensitization to Parietaria judaica; grass pollen; house dust mites; Olea europea: orchard; perennial rye; and cat allergens). Female sex, sensitization to Parietaria judaica and the presence of pets in the home were also significantly predictive of new onset asthma in the same model. Treatment with allergen immunotherapy was significantly and inversely related to the development of new onset asthma (OR, 0.53; 95%CI, 0.32–0.86).In the present study we found that allergic rhinitis is an important independent risk factor for asthma. Moreover, treatment with allergen immunotherapy lowers the risk of the development of new asthma cases in adults with allergic rhinitis.