Asthma is more frequently associated with non-allergic than allergic rhinitis in Portuguese patients.

BACKGROUND: Rhinitis prevalence is increasing worldwide and is frequently associated with asthma, for which it is a risk factor. The aims of the study were to characterise the adult population with rhinitis attending the Cova da Beira Hospital Allergy Clinic, and to assess the relationship between rhinitis and asthma. METHODS: In total, 686 patients were characterised by clinical history and anterior rhinoscopy, and classified according to international guidelines. Atopy was determined by skin prick testing to aeroallergens and quantification of specific IgE. RESULTS: Seventy two percent of patients had allergic rhinitis (AR), and 28% had non-allergic rhinitis (NAR). NAR was more frequently associated with older age, perennial symptoms and female gender. NAR patients more frequently had bronchial asthma. In addition, more NAR than AR patients also had drug allergy, pharyngitis, sinusitis and urticaria. AR patients with nasal polyps more frequently had asthma. Grass pollen and mites were the major sensitisers for AR patients. Sensitisation profiles were not significantly different between urban- and rural-based AR patients. CONCLUSIONS: Asthma was more frequently associated with non-allergic than with allergic rhinitis. The two types of rhinitis did not differ in clinical severity. Although sensitisation profiles were not different between the urban and rural patients, allergic rhinitis prevalence was higher in urban patients.