Sensitization to aeroallergens among patients with allergic rhinitis in a desert environment

Background: The causative allergens of allergic rhinitis in desert environm ents are uncertain. Objective: To determine the sensitizing aeroallergens in patients with alle rgic rhinitis in Kuwait, a desert country. Methods: A total of 706 patients aged 6 to 64 years (mean 34.3 years) with allergic rhinitis were studied. Sera from the patients were screened for sp ecific IgE to 14 inhalant allergens by the CAP-RAST method. Results: Specific IgE to any allergen was detected in 86.3% of patients. Th e prevalence rates for allergen groups were: pollens (77.3%), house dust (6 2.3%), and molds (14.7%). The individual allergens with the highest positiv e rates were pollens of the weed Chenopodium (64.3%); Bermuda grass (55.0%) , and Prosopis tree (50.3%). These plants were all imported and cultivated for the purpose of "greening" the desert. German cockroach (48.2%) and hous e dust mites (32.4% to 39.2%) were the most prevalent indoor sensitizers. W ith the exception of the molds, sensitization rates were higher for males t han females. The youngest age group (6 to 17 years) had significantly highe r sensitization rates than the older ones, particularly with respect to the molds (P < .01 to .001). Severe sensitization was more common with Alterna ria than the other allergens and in general mold sensitization was more fre quently associated with severe symptoms. Polysensitization was very common, with 81.8% of all sensitized patients positive to more than one allergen. Conclusions: Pollens of the local horticultural plants are the main sensiti zing allergens among patients with allergic rhinitis in this desert environ ment. The practices that "green" the desert seem to also encourage allergen sensitization.