First Bite Syndrome: Our Experience at a Tertiary Care Centre

Abstract

Introduction: First bite syndrome is a potential complication of surgery involving the infratemporal fossa, deep lobe of the parotid gland, parapharyngeal space, carotid body tumors, and various head and neck malignancies. It is described as acute and intense pain in the parotid region caused by the rst bite of each meal which gradually improves with the subsequent bites. Various treatment strategies have been employed with no signicant therapeutic benet. This study brings out our experience of rst bite syndrome at a tertiary care center. Materials and Methods: A retrospective study was conducted to identify the patients who developed rst bite syndrome with or without Horner's syndrome at a tertiary care hospital from Jan 2020 to Dec 2022. Patient records were accessed to gather data on patient demographics, presenting symptoms, and surgical history. Atotal of 80 patients were included in the study. Patients were operated by Head and Neck Oncosurgeon, assisted by Vascular Surgeon. 51 of them were males while 29 were females. Once the diagnosis of FBS was made, the time of onset since surgery, duration of symptoms, and associated symptoms of Horner's syndrome were noted. Results:Atotal of 80 patients were included in the study. 51 of them were males while 29 were females. The mean age of patients was 43 years. 16.25 % of the total patients developed FBS. Out of the 80 patients, seven patients underwent excision of vagal schwannoma, two of them developed only rst bite syndrome while the rest ve developed rst bite syndrome with Horner's syndrome. Total parotidectomy was indicated for four patients for mucoepidermoid carcinoma. Two patients underwent excision of paraganglioma and branchial stula respectively. The remaining patients who did not develop FBS underwent excision of the carotid body tumor (8), supercial parotidectomy (23), and total parotidectomy (36). Discussion: The cause of FBS is largely unknown, however, Netterville et al have proposed that FBS is caused by the loss of sympathetic innervation to the parotid gland–– . Netterville et al proposed that FBS is due to the damage or removal of cervical sympathetic with loss of sympathetic innervations to the parotid gland. It is interesting to note that in our study out of the 40 patients who underwent total parotidectomy only four patients developed rst bite syndrome. Given the extreme rarity of this syndrome compared to the relatively high rate of external carotid artery and/or parotid gland surgery with ligation or resection of the external carotid artery, sympathetic parasympathetic conict on myoepithelial cells of the parotid gland is probably not the only mechanism involved in the pathogenesis of this syndrome, whose pathophysiology has not yet been fully understood– . Various treatment strategies have been proposed to relieve the pain of rst bite syndrome. Non-steroidal anti-inammatory drugs, acupuncture, anesthetic sprays or local anesthetic block and oral analgesics such as paracetamol, codeine, or narcotics, and tympanic neurectomy or auriculotemporal neurectomy have remained ineffective. Conclusion: The rst bite syndrome is a relatively rare condition occurring as a result of a sympathetic-parasympathetic imbalance in the innervations to the parotid gland. Although most of the studies support this hypothesis there may be other factors in play owing to the rarity of this syndrome as compared to the number of neck surgeries performed. Various treatment options have been tried but none has shown a signicant therapeutic benet