Background: Asthma is a heterogeneous chronic inflammatory condition characterised by reversible airway obstruction and hyperresponsiveness associated with underlying bronchial inflammation and structural changes. It represents an increasing health problem and is a huge burden on the patients, their families and society. The aim of the study was to characterise the adult asthmatic population attending a Hospital Allergy Clinic between the years of 2003 and 2006.
Methods: Clinical files from the Allergy Outpatient Clinic of Cova da Beira Hospital were sequentially studied. The total population analysed included 335 female and 130 male asthmatic patients. Bronchial asthma was characterised by clinical history, skin prick testing to aeroallergens, determination of total and specific IgE and lung function testing, and classified according to international guidelines.
Results: Of the patients studied, 70 % had allergic asthma, and 30 % had non-allergic asthma. When compared to allergic asthma, non-allergic asthma was more frequently associated with older age, perennial symptoms and female gender. More allergic than non-allergic asthma patients also had rhinitis and the reverse was true regarding drug allergy and oesophageal reflux. Grass pollen and mites were the major sensitisers for allergic asthmatics. The sensitisation profile was significantly different between urban- and rural-based asthmatic patients regarding tree pollen, fungi and moulds.
Conclusions: In this population, rhinitis was more frequently associated with allergic than with non-allergic asthma. The two types of asthma did not differ in clinical severity or changes in lung function. Sensitisation profiles were different between the urban and rural patients.