Gustatory sweating (Frey's syndrome or auriculotemporal syndrome) Frey syndrome, also known as auriculotemporal syndrome or gustatory sweating, is characterized by sweating and flushing of the facial skin over the parotid bed and neck during mastication (in the cutaneous distribution of the auriculotemporal nerve.)It is caused by injury to auriculotemporal nerve, after surgical trauma to the parotid gland. Frey syndrome is thought to be due to aberrant regeneration of cut parasympathetic fibers between the otic ganglion and salivary tissue, which leads to innervation of sweat glands and subcutaneous vessels. Frey syndrome is reported by approximately 10 percent of patients, although rigorous testing may detect gustatory sweating in as many as 95 percent of patients after parotidectomy. Frey syndrome may occur from two weeks to two years after surgery due to a latency in the regeneration of parasympathetic nerve fibers; the area of involved skin may increase over time. The incidence of Frey syndrome is reduced by minimizing the parotid wound bed, placing fascial grafts between the skin and the gland bed, reconstructive techniques such as thick skin flaps, and postoperative RT. Intracutaneous injection of botulinum toxin A is an effective, well-tolerated, and long-lasting treatment for symptomatic patients; it may be repeated for recurrent symptoms.