First bite syndrome: Our experience with intraparotid injections with botulinum toxin type A.

[OBJECTIVES/HYPOTHESIS] First bite syndrome is the sudden onset of acute and severe pain in the parotid region at the initiation of mastication. Although it generally lasts less than a minute, it is disabling for these individuals and leads to a fear of oral intake. It is typically seen after parapharyngeal or deep parotid space surgery. Intraparotid injection of botulinum toxin A (BTA) has been suggested as a treatment for this condition, but there is little supporting literature to this effect. The purpose of this study is to document our experience using this treatment method for first bite syndrome.

[STUDY DESIGN] Retrospective case review.

[METHODS] Five patients with first bite syndrome, developed after parapharyngeal space surgery, were treated by multisite injection of BTA into the parotid gland. Between 17.5 and 50 total U of BTA were injected into four or more sites in the parotid region. The patients were then followed up every 4 months.

[RESULTS] Three of five patients reported a significant improvement in symptoms at the 4-month follow-up visit, although complete resolution was not reported. One patient reported only moderate improvement, and despite two series of injections there was no improvement in one patient, leading us to question our initial diagnosis.

[CONCLUSIONS] Unilateral BTA injection into the affected parotid gland produces a decrease in the severity of symptoms. It is a safe and viable noninvasive treatment for this difficult to treat condition and may lead to permanent resolution of symptoms in some patients.