Idiopathic first bite syndrome - A rare case report with review of literature.

First bite syndrome (FBS) is a condition that classically presents as severe pain in the preauricular region, initiated on the first bite of a meal. In most of the cases reported, it is associated with a history of upper neck surgery or tumor of the parotid salivary gland or parapharyngeal space (PPS). Some propose that FBS arises due to damage to the cervical sympathetic trunk leading to the loss of sympathetic innervations to the parotid salivary gland. Literature also showed occurrence of this syndrome in individuals who had no history of parotid tumor, PPS tumor or surgery of the upper neck, and such cases are referred to as idiopathic FBS (IFBS). There are very few case reports reported on IFBS. We report the one such rare case of IFBS in a 35-year-old male, referred to the outpatient department, with a 5-month history of severe, sharp pain and bilateral swelling in the parotid region occurring only on the first bite of eating and would diminish over few minutes.