Comorbid allergy and rhinitis and patient-related outcomes in asthma and COPD: a cross-sectional study.

Introduction: The study aimed to compare prevalence of comorbid allergic manifestations and rhinitis, allergy testing and associations with patient-related outcomes in patients with asthma and COPD.

Methods: Cross-sectional study of randomly selected Swedish patients with a doctor's diagnosis of asthma (n = 1291) or COPD (n = 1329). Self-completion questionnaires from 2014 provided data on demographics, rhinitis, allergic symptoms at exposure to pollen or furry pets, exacerbations, self-assessed severity of disease and scores from the Asthma Control Test (ACT) and the COPD Assessment Test (CAT), and records were reviewed for allergy tests.

Results: Allergic manifestations were more common in asthma (75%) compared with COPD (38%). Rhinitis was reported in 70% of asthma and 58% of COPD patients. Allergy tests had been performed during the previous decade in 28% of patients with asthma and in 8% of patients with COPD.In patients with asthma; comorbid allergy and rhinitis were both independently associated with increased risk for poor asthma symptom control (ACT < 20) (OR [95% CI] 1.41 [1.05 to 1.87] and 2.13 [1.60 to 2.83]), exacerbations (1.58 [1.15 to 2.17] and 1.38 [1.02 to 1.86]), and self-assessed moderate/severe disease (1.64 [1.22 to 2.18] and 1.75 [1.33 to 2.30]). In patients with COPD, comorbid allergy and rhinitis were both independently associated with increased risk for low health status (CAT ≥ 10) (OR [95% CI] 1.46 [1.20 to 1.95] and 2.59 [1.97 to 3.41]) respectively, with exacerbations during the previous six months (1.91 [1.49 to 2.45] and 1.57 [1.23 to 2.01]), and with self-assessed moderate/severe disease (1.70 [1.31 to 2.22] and 2.13 [1.66 to 2.74]).

Conclusion: Allergic manifestations and rhinitis are more common in asthma than COPD but associated with worse outcomes in both diseases. This highlights the importance of examining and treating comorbid allergy and rhinitis, not only in asthma but also in COPD.