30-Unit Dose of Abobotulinum Toxin A Reduces Most Nasal Allergic Rhinitis Symptoms

What is the lowest effective dose of abobotulinum toxin A injection for allergic rhinitis?

BOTTOM LINE: Abobotulinum toxin A at a dose of at least 30 U effectively reduces most nasal symptoms.

BACKGROUND: Used to treat allergic rhinitis since 1998, botulinum toxin A is formulated in three, noninterchangeable types: onabotulinum toxin A, abobotulinum toxin A, and incobotulinum toxin A. There is no standard recommended dose of botulinum toxin for allergic rhinitis; however, exceeding the minimum effective dose increases side effect risk.

STUDY DESIGN: Dose-escalation randomized controlled trial.

SETTING: Department of Otorhinolaryngology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.

SYNOPSIS: Researchers randomly allocated doses of abobotulinum toxin A to 17 patients who had persistent allergic rhinitis and positive allergy skin prick tests. Seven patients received an injected dose of 20 U of abobotulinum toxin A, five patients received 30 U, and another five received 40 U. The total dose for each arm was divided at a 50:50 ratio and injected over five minutes into the anterior part of the inferior turbinate on each side under a rigid endoscope. Follow-up lasted three months, with outpatient evaluations or telephone interviews conducted at weeks one, two, four, eight, and 12. A five-point Likert scale was used to evaluate nasal obstruction, rhinorrhea, sneezing, nasal itching, inhibited sense of smell, and eye itching, redness, and watering. Objective outcomes included findings from nasal endoscopy and acoustic rhinometry. Results showed that abobotulinum toxin A significantly improved nasal congestion, rhinorrhea, sneezing, and loss of smell at 40 U, and nasal congestion, sneezing, and loss of smell at 30 U, but at the 20 U dose, only nasal congestion and loss of smell improved.

CITATION: Piromchai P, Pornumnouy W, Saeseow P, et al. The minimum effective dose of abobotulinum toxin A injection for allergic rhinitis: A dose-escalation randomized controlled trial [published online ahead of print December 8, 2020]. Laryngoscope Investig Otolaryngol. doi: 10.1002/lio2.499.