Introduction Idiopathic rhinitis is a nonallergic and noninfectious rhinitis characterized by nasal obstruction and rhinorrhea, resulting from an autonomic imbalance. Botulinum toxin type A (BTX-A) demonstrated its action in reducing rhinorrhea and nasal obstruction when injected into the nasal turbinates or septum.

Objective To analyze the effects of intranasal BTX-A injection to control the symptoms of idiopathic rhinitis and its possible adverse effects.

Method Patients with idiopathic rhinitis were divided into two groups. Group A had 15 participants (8 female and 6 male), of ages from 47 to 84 years (mean 66.57 years), and these received 60 U of Dysport (Ipsen Ltd, Maidenhead, Berkshire, UK) in each inferior nasal turbinate; group B had 12 participants (1 male and 11 female), of ages from 50 to 76 years (mean 60 years), and they received 1ml of 0.9% saline. The individuals were reevaluated in the 1st, 2nd, 4th, 8th, and 12th weeks after injection by a questionnaire, accompanied by nasal inspiratory peak flow and acoustic rhinometry. 

Results Group A showed significant improvement regarding the symptoms of sneezing/itching and nasal obstruction, over time and when compared to group B. Acoustic rhinometry confirmed the improvement in nasal obstruction. There was no relationship between the nasal peak flow data and the nasal obstruction score. No major adverse effects have been reported.

Conclusion The injection of botulinum toxin in the inferior nasal turbinates of patients with idiopathic rhinitis reduces the symptoms of sneezing, itching, nasal obstruction, and runny nose without significant adverse effects, suggesting that it is an option in the treatment of these patients.