Effects of a topical microemulsion in house dust mite allergic rhinitis

We have previously demonstrated that a topical microemulsion can attenuate symptoms and signs of seasonal allergic rhinitis. This likely reflects that the microemulsion interferes with the interaction between the allergen and the mucosa. Whether or not the finding translates to conditions caused by other inhaled agents such as house dust mite allergen is unknown. Patients with perennial allergic rhinitis caused by house dust mite were subjected to topical microemulsion treatment in a randomized, double-blinded and crossover design with isotonic saline as control. Morning symptoms were monitored, change from baseline was assessed and the treatments were compared. On the first days of the isotonic saline and microemulsion runs, before any treatment was given, total nasal symptoms were scored to 2.8 and 3.1 (range 0-9), respectively. Nasal symptoms were reduced by intervention with the microemulsion: the change from baseline was consistent for the microemulsion and the difference between the microemulsion and isotonic saline reached statistical significance in favour of the former. We conclude that intervention with a microemulsion may reduce symptoms of house dust mite allergic rhinitis at natural allergen exposure. Our findings suggest the possibility that topical microemulsions can be a useful option to reduce nasal mucosal exposure to allergen in perennial allergic rhinitis..