Low-dose local nasal immunotherapy in children with perennial allergic rhinitis due to Dermatophagoides.

BACKGROUND Allergen specific immunotherapy was known to be useful in the treatment of respiratory allergic disease. Local nasal immunotherapy (LNIT) offers advantages such as a good efficacy/safety ratio and a more convenient allergen delivery. The aim of this study was to assess the safety and clinical efficacy of a modified scheduling of LNIT in 32 children with allergic rhinitis due to Dermatophagoides. METHODS A multicentre, randomized, double-blind placebo controlled study carried out for two years, with a modified schedule of LNIT treatment: a build-up phase at increasing dosages from 2.5 AU to 80 AU and a maintenance period at low dosage (80 AU) once a week. Symptom and medication scores. threshold dose with specific nasal provocation test (NPT) and immunological parameters (IgE and IgG4) were evaluated. RESULTS No important local or systemic side-effects were observed in children who completed the study. Compared to placebo, the active treatment group showed significant improvement in rhinitis symptoms and a reduction of drug consumption after 18 months of LNIT. These results were confirmed by a significant reduction of allergen specific nasal reactivity. Serum and nasal specific IgE and IgG4 did not show any difference in the two groups. CONCLUSIONS The safety and clinical efficacy of low-dose LNIT suggests that this therapy may be useful in the treatment of allergic rhinitis disease in children.