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 buildup 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 IgG(4)) 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.