Environmental priming influences allergen-specific nasal reactivity

Background Preceding mucosal response to one allergen leads to the priming of the nasal mucosal response to another allergen. This study aimed to dete rmine whether environmental allergens, especially ubiquitous animal dander, can induce nasal priming. Methods We investigated 26 grass-pollen-allergic subjects with additional s ensitization to other aeroallergens. We performed continuous allergen chall enge for 2 h with 1500 Dactylis glomerata pollen/m(3) in the Vienna challen ge chamber. The nasal flow at 150 Pa was examined, and subjective scores we re obtained every 15 min. Statistical analysis was calculated from the area under curve of nasal flow reduction by Student's t-test and the Mann-Whitn ey U-test. Alpha was 0.05. Results In subjects with positive cat-dander PAST (class of greater than or equal to 3), besides grass-pollen allergy, the specific nasal allergic rea ction to Dactylis challenge was significantly pronounced (P<0.01), and an e arlier onset of reaction was evident. The same results were obtained with a dditional sensitization to dog dander (P<0.05). Concomitant sensitization t o mugwort also led to escalating symptoms (P<0.05). Conclusions These results indicate that a specific nasal allergic reaction is augmented by environmental priming caused by ubiquitous animal dander an d possibly is influenced by the daily use of spices.