Epidemiological characteristics and allergen sensitization patterns in subjects with intermittent allergic rhinitis

Background: Under the ARIA guidelines, allergic rhinitis (AR) is classified as intermittent (IAR) or persistent (PER) disease depending on the duration of symptoms. In addition, AR may co-exist with or exacerbate allergic co-morbidities. As part of a prospective study of desloratadine (DL) in the treatment of IAR, we studied the epidemiology of concomitant allergic diseases and allergen sensitization patterns internationally. Methods: This was a multi-national, randomized, placebo-controlled, parallel-group study of DL 5mg and Placebo QD administered for 15 days in subjects with ARIA-defined IAR. At screening, subjects underwent skin testing for sensitization to prevalent allergens; where possible the GALEN allergen panel was employed. Eligible subjects were aged ≥12 yrs, had a diagnosis in keeping with IAR for ≥2 yrs and were skin-test positive (wheal >3mm more than diluent control) to ≥1 relevant allergen. Subjects had to have symptomatic IAR at screening. Demographic and concomitant allergic disease characteristics were recorded at screening; these data and allergen skin-test responses were pooled for the entire population and were reported descriptively. Results: The study enrolled 547 subjects in 14 countries in Europe (incl. Russia and Turkey) and Canada. Overall 58% of the population was female and 91% was Caucasian. The mean (±SD) age was 34.2±12.4 yrs (range: 13-72 yrs), while the mean height and weight were 169.5±9.3 cm and 71.2±15.5 kg, respectively. Overall, 16.8% reported having allergic asthma, 15.2% reported concomitant food allergy and 10.6% had atopic dermatitis. Among the entire study population the most frequent relevant positive skin-prick tests were as follows: grass mix (40.1%), D. pteronyssinus (37.9%), D. farinae (31.7%), cat (22.5%), birch (22.3%), hazel (17.6%), alder (16.3%), ragweed/ambrosia (15.8%), dog (12.6%), parietaria (9.5%) and alternaria (8.61%). Among European countries, allergen sensitization frequencies were as follows: grass mix (57.1%), D. pteronyssinus (36.3%), D. farinae (29.4%), birch (28.3%), cat (23.6%), hazel (20.1%), alder (15.9%), dog (15.1%), parietaria (14.3%) and artemisia (11.5%). Conclusion: In subjects with ARIA-defined IAR, allergic co-morbidities of the lower airway, gut and skin were also prevalent. Subjects with IAR demonstrate sensitization to a variety of seasonal and year-round allergens; geographical differences in allergen sensitization patterns were seen.