Association of allergy-related symptoms with sensitisation to common allergens in an adult European population

Background: Atopy is an important risk factor for asthma and allergic disea ses. However, the relationship between atopy and allergic symptoms is not f ully understood, and may not be the same for different allergy related symp toms and in differing environmental conditions. Objective: To study the dif ferences in the association of allergy-related symptoms and atopy, in an ad ult population from five European countries. Methods: A prospective, multi- national study was conducted. Centres included Isle of Wight (UK), Vienna ( Austria), Freiburg (Germany), Athens (Greece), and Kaunas (Lithuania). We u sed five questions derived from the ISAAC (International Study of Asthma an d Allergy in Children) and other validated questionnaire, to evaluate the p resence of allergic symptoms in a selected adult population. Atopy was asse ssed by SPT or IgE measurement to 3 core allergens (dust mite, cat and gras s pollen) in all centres and 1-2 additional allergens relevant to each area (parietaria, olive, birch pollen, tree pollen mix, dog). Results: Of 3985 subjects, 2478 (62%) responded positively to one or more core ISAAC questio ns. Sensitisation rate was high in Austria and UK and relatively low in Gre ece. Dust mite and cat were important allergens for asthma, odds ratio (OR) : 2.24, 95% confidence interval (Cl): 1.63-3.08 and OR: 2.31, CI: 1.69-3.14 , respectively. Grass pollen was strongly associated with hay fever in all centres (OR: 3.62 CI: 2.81-4.66) and with birch pollen in Austria (OR: 3.57 , Cl: 2.09-6.09) and with parietaria in Greece (4.61 (2.99-7.12). In the co mparative analysis, using UK as a reference, Lithuanians had a 10-20-fold r educed risk of asthma and hay fever, but were twice more likely to report c hronic itching. The risk of dust mite allergy was 3- and 10-fold lower in L ithuania and Greece, respectively, whereas the risk of cat and grass pollen allergy was one and half times higher in Austria. Conclusion: The risk of allergic symptoms and sensitisation and their association vary widely in di fferent European countries.