Objectives: In this study, we examined the effect of botulinum toxin A (BTA) on chronic allergic rhinitis (CAR). We tested the effects of BTA, applied to an intranasal sponge, on patients who had CAR for a minimum of three years and had been treated unsuccessfully with conventional medications.

Methods:The study was an interventional case-control single-blind randomized clinical trial. Forty-four male and female CAR patients who were referred to Tehran’s Saee & Pasargad Hospitals, and Saadat-Abaad, Sarv and Karimkhan Clinics in 2012 aged 20-40 years were selected on the basis of inclusion and exclusion criteria. The subjects were randomly assigned to the intervention (n=22) or control group (n=22). The intervention group received BTA (100 IU/ml Dysport), on a 5cm nasal sponge retained in each nasal cavity for 30 minutes. The control group received normal saline. The groups were evaluated by the same examiner. Pre-and post-tests (1, 3, 6, and 12 weeks) were performed according to the authors’ pre-designed checklist, the validity and reliability of which was previously established. The symptoms scored from none (0) to severe (10) at the test points. The statistical analysis was conducted with SPSS-19, with a significance level of 0.05.

Results: Based on ANOVA, there was a significant difference (P<0.05) in symptomatic relief between the intervention and control groups. No marked adverse effects were observed during the study.

Discussion: An intranasal 5cm sponge impregnated with 100 IU/ml BTA, retained in each nasal cavity for 30 minutes, may alleviate CAR symptoms with no significant adverse effects.