Aeroallergen IgE-Reactivity Patterns and Respiratory Allergy in Children and Adults: A Retrospective Study in 1711 Patients from the Central Poland Urban Area

<i>Background and Objectives</i>: Effects of allergen exposure may be modified through endogenous and exogenous factors, resulting in heterogeneity of clinical features, time course and intensity of symptoms of allergic disease. This creates challenges in allergy diagnosis and management, yet studies addressing the variability of allergen reactivity in relation to potential modifying factors are not numerous. The aim of the study was to retrospectively analyze the frequency and profile of reactivity to inhalant allergen extracts in patients followed in a single center in the years 2017-2020, in relation to sex, age, clinical symptoms and final clinical diagnosis. <i>Materials and Methods</i>: This is a retrospective analysis of skin prick test (SPT) results in 1711 outpatients, performed with dust mites, pollen (alder, hazel, birch, grasses, rye, mugwort), cat, dog and <i>Alternaria</i> allergens. Reactivity profiles were assessed in the entire population divided into sex and age subgroups. Relationships between SPT results, age, sex and clinical diagnosis were assessed using factor analysis. <i>Results</i>: The highest reactivity frequencies were found for grass (60.5%), rye (57.22%), birch (47.34%), alder (42.5%) and <i>Dermatophagoides pteronyssinus</i> mites (41.8%). Monovalent reactivity was found mainly to mugwort (3.2%, n = 55), followed by cat and mites allergens. Reactivity to ≥1 allergen was more frequent in males. The risk of allergic rhinitis (AR) was significantly higher in subjects allergic to grass, rye, hazel and alder pollen, as compared to subjects non-sensitized to these allergens. Reactivity to perennial allergens (dog, cat and dust mites) was significantly associated with asthma diagnosis. The risk of developing atopic dermatitis was significantly associated with reactivity to birch and alder pollen. <i>Conclusions</i>: SPTs are a valuable tool for assessing the occurrence of atopy and allergy. Reactivity to specific aeroallergens may be associated with increased probability of development of a given atopic condition. This warrants further studies regarding the interplay between possible modifiers of allergen exposure effects.