Background: The prevalence of allergic diseases, mainly pollinosis, has increased within the last decades. Our study aimed to determine the prevalence of sensitization to Poaceae pollen in the Basque Country. This is a region of northern Spain, with an area of 7261 km2 and a population of 2109009 inhabitants. Two different climatic regions may be distinguished in the Basque Country (the Atlantic and the Oceanic).
Methods: A transversal study was carried out on 2216 subjects, aged 10–40 years. A personal interview was carried out in order to compile study data, by means of a questionnaire that had been previously validated with a clinical history and an allergy study.
Results and Conclusions: Our results show the prevalence of pollinosis in the Basque Country to be 10.6% (C.I. 95% 9.35–11.96%) without significant differences between men and women. The prevalence in the Atlantic climate area (9.71%) was lower than in the Oceanic climate area (13.61%). There were no differences between persons living in a rural environment (10.87%) and those living in an urban setting (10.51%). Pollinosis was more frequent in individuals aged 10–20 (11.41%) and 20–30 (12.54%) than those aged 30–40 years (7.43%). Three features significantly distinguished pollinic from nonpollinic patients:
a more common complaint of symptoms after ingestion of Rosaceae fruits or nuts (10.2%)
a family history of atopy (8.8%)
a greater occurrence of bronchial asthmatic symptoms (23%).