The prevalence of IgE-dependent sensitizations to selected trophoallergens and airborne allergens in the population of children and adolescents of the north-eastern region of Poland

Introduction
Good evidence has been provided over the last three to four decades that the prevalence of allergic diseases has been increasing in many developed countries worldwide. Recent data suggest that this increase may now be levelling off.

Aim
Retrospective analysis of the prevalence of IgE-dependent sensitization and changes in selected environmental allergens in the population of children and adolescents in the north-eastern region of Poland in the years 1998–2012.

Material and methods
Skin prick testing (SPT) with selected food allergens (trophoallergens) and airborne allergens was used to evaluate the sensitization process of patients recruited to the study in the years 1998–2012. A positive result of sensitization was defined when the patient had at least one positive skin prick test with the allergen studied. The skin prick tests were done after written consent had been obtained from the parents.

Results
The retrospective study included children and adolescents aged up to 18 years with a suspicion of an allergic disease, referred to the regional tertiary medical centre for further diagnosis. A total of 6577 patients were studied, including 1556 (23.7%) in 1998, 1473 (22.4%) in 2003, 1690 (25.7%) in 2008, and 1858 (28.2%) in 2012. Sensitization to at least one allergen was observed in 39.0% of the examined children (regardless of the allergen type), of which 8.1% were sensitized to food allergens only, 23.9% to airborne allergens only, and 7.0% simultaneously to food and airborne allergens. During the 14-year study period, an increase was noted in the percentage of the sensitized children from 35.3% at baseline to 40.4% when the study was completed. The percentage of those sensitized to food allergens increased from 10.5% (1998) to 20.1% (2012). The percentage of children sensitized to airborne allergens remained unchanged at the level of 28.2% in 1998 and 27.2% in 2012.

Conclusions
Measurement of skin prick test reactivity to different allergens is a useful and commonly used method in epidemiological studies for the assessment of allergic sensitization and changes in selected populations. The obtained results confirmed the need for systematic epidemiological research into allergic sensitization and allergic diseases among children and adolescents in Poland.