Sublingual immunotherapy for Alternaria-induced allergic rhinitis: a randomized placebo-controlled trial

Background: Respiratory allergy due to Alternaria is a relevant clinical problem, and specific immunotherapy may represent a viable treatment option. Sublingual immunotherapy (SLIT) is safe and effective, but data for Alternaria are lacking.

Objective: To assess the efficacy of standardized SLIT in patients sensitized to Alternaria in a randomized, prospective, double-blind, placebo-controlled trial.

Methods: Patients with rhinitis with or without intermittent asthma and ascertained allergy to Alternaria were enrolled. After a baseline season, SLIT or matched placebo was given for 10 months. Symptoms and rescue medication intake were recorded on diary cards between June and October. Skin prick testing was performed and specific IgE, IgG4, and precipitin levels were measured at baseline and at the end of the study.

Results: Twenty-seven patients (age range, 14-42 years) were randomized, and 26 completed the study. The baseline characteristics were homogeneous in the 2 groups. After treatment, patients receiving SLIT had a significant improvement in symptoms and a reduction in medication intake vs placebo and vs the run-in season, whereas no change was seen in the placebo group. Skin prick test reactivity significantly decreased only in the SLIT group. No change was seen in specific IgG4 levels in the 2 groups, whereas Alt a 1 specific IgE levels significantly increased in the active group. One patient in the active group reported oral itching and conjunctivitis at the beginning of treatment.

Conclusion: SLIT seems effective and safe and may represent a valuable therapeutic option in respiratory allergy due to Alternaria.