Conclusions: Intranasal microemulsion treatment can attenuate allergen challenge-induced nasal symptoms and plasma exudation in allergic rhinitis. We hypothesize that the mechanism of action involves modification of the allergen-mucosa interaction. The present observation suggests a novel principle for prevention in allergic rhinitis.
Objective: To evaluate a specific microemulsion as a treatment for allergic rhinitis in an acute allergen challenge model.
Patients and methods: Patients with allergic rhinitis were examined out of the pollen season. Treatment with a single dose of a specific microemulsion was given in a single-blind, placebo-controlled, and crossover design using a nasal pool device. Nasal allergen challenges were carried out and symptoms of allergic rhinitis were scored. Furthermore, nasal lavages were performed and levels of the plasma protein alpha 2-macroglobulin were measured as an index of exudative inflammation.
Results: The allergen challenges produced significant increases in nasal symptoms (p=0.007) and in nasal lavage fluid levels of alpha 2-macroglobulin (p=0.008). The challenge-induced symptoms as well as the plasma exudation were attenuated by treatment with the microemulsion (p=0.016 and 0.012, respectively, compared with placebo).