First bite syndrome: A complication of surgery involving the parapharyngeal space

Introduction. First bite syndrome (FBS) is the development of pain in the parotid region after the first bite of each meal and can be seen after surgery of the parapharyngeal space. The cause is not clear but has been proposed to involve a loss of sympathetic nerve function to the parotid, causing a denervation supersensitivity of salivary gland myoepithelial cells. The purpose of this study was to review the records of 12 patients with FBS to determine any common features of the operations performed that would support this theory of parotid "sympathectomy" as an etiologic factor of FBS. Methods. Retrospective review of 12 patients with FBS managed at two tertiary care centers. Results. Twelve patients were diagnosed with FBS after surgery involving the parapharyngeal space. All patients had most of their parotid gland preserved. Six patients exhibited a postoperative Horner's syndrome, suggesting sympathetic chain interruption. The six patients without Horner's syndrome were found to have undergone external carotid artery ligation inferior to the parotid gland, suggesting an interruption of sympathetic innervation to the parotid gland itself. Conclusions. Preservation of parotid gland tissue and a loss of its sympathetic nerve supply, whether by disruption of the cervical sympathetic chain as evidenced by a Horner's syndrome or more selective denervation by ligation of the external carotid artery with its accompanying sympathetic nerve plexus, were common features of all patients. This series supports the concept of parotid "sympathectomy" as an etiologic factor in FBS.