Objective: To assess the efficacy and safety of specific local nasal immunotherapy (LNIT) in powder form in patients with allergic rhinitis, using subjective and objective parameters.
Study design: A double-blind randomized multicenter trial of 102 patients with allergic rhinitis who were treated with specific LNIT for 8 consecutive months.
Methods: After identifying allergens with the skin prick test and sensitization threshold dose with the specific nasal provocation test, 102 patients were selected, of whom 55 were allergic to mites and 47 were allergic to Graminaceae or Parietaria pollen. The specific treatments were self-administered using an insufflator in two phases (phase 1: increasing doses; phase: 2, maintenance dose). Patients were evaluated before and after 32 weeks of treatment by subjective analysis of their self-reported symptoms and by objective analysis of nasal provocation test, nasal resistance by anterior rhinomanometry, and mucociliary clearance time.
Results: Clinical efficacy of LNIT for allergy to mites and pollens was confirmed by the differences in the symptoms score between the active group and the placebo group. The nasal provocation test results confirmed that this difference was statistically significant. The rhinomanometric analysis gave positive results for the treated group mainly in LNIT for mites. No differences in mucociliary clearance time were found.
Conclusions: Specific LNIT is effective for allergic rhinitis and appears to offer considerable advantages over other hyposensitization methods. It can be done at home, patient compliance is good, and the treatment is safe.