Background: Several studies have shown links between the upper and lower airways in allergic patients.
Objectives: This study aimed to evaluate the prevalence of rhinitis in patients with allergic asthma attending allergy outpatient clinics and to examine the interrelationship between both conditions.
Methods: An epidemiological prospective study was carried out during the period 2004-2005 and 170 allergists from all over the country participated. After obtaining written informed consent, we collected clinical and demographic data, a personal and family history of allergic diseases, and data on the duration and severity of asthma and rhinitis. These data were classified according to the criteria of the Global Initiative for Asthma and the Allergic Rhinitis and its Impact on Asthma guidelines, respectively.
Results: A total of 968 subjects were screened and 942 were enrolled in the study. Mean (SD) age was 35.5 (14) years and 63% were female. Of these patients, 89.5% presented with allergic rhinitis. The duration of the disease was 12.6 (8.9) years for rhinitis and 11.4 (9.6) years for asthma (P < .0001). The severity of asthma was classified as intermittent (39%), mild persistent (30%), moderate persistent (27%), and severe persistent (4%). Rhinitis was classified as mild intermittent (24%), moderate/severe intermittent (22%), mild persistent (19%) and moderate/severe persistent (35%). A significant correlation was found (P < .0001) between the severity of rhinitis and asthma. The prevalence of allergic rhinitis was inversely correlated with the age of the patients (P < .0001) and the severity of asthma (P < .05).
Conclusion: This study reinforces the high prevalence of allergic rhinitis in patients with asthma, which can affect as many as 89.5%.