Objectives: To estimate the prevalence of diagnosis of allergic asthma in patients with persistent asthma attending allergy or pneumology outpatient clinics and to describe the clinical management of asthma in these patients.
Methods: Systematic random sampling was used to retrospectively include 382 patients aged between 12 and 65 years old with a diagnosis of persistent asthma (according to GINA criteria) who had attended allergy or pneumology outpatient clinics during the previous year. Allergic asthma was defined as the presence of sensitization to any common allergen according to the results of specific IgE determinations and/or skin tests. Data on the treatment of asthma were gathered.
Results: Allergy studies were performed in 99.5% of the patients attending allergy centers and in 76.5% of those attending pneumology centers. A diagnosis of allergic asthma was made in 90.6% (95% CI: 86.5-94.7) and 46.1% (95% CI: 39.0-53.2), respectively. The prevalence of allergic asthma was highest in young male patients with less severe asthma. According to the GINA criteria, 14.1% of patients from allergy centres and 23.0% of those from pneumology centers were classified as having severe persistent asthma. Twenty-four percent of patients attending allergy clinics and 5.7% of those attending pneumology centers received bronchodilator treatment exclusively.
Conclusions: Diagnosis of allergic asthma was much higher in allergy clinics than in pneumology centres. Although some of this difference may be due to more frequent performance of allergy studies in allergy clinics, the most probable explanation lies in the differences observed in the profiles of patients attending the two types of center.