Gustatory flushing and sweating is a common complication of parotidectomy. This syndrome, usually called Frey syndrome, is presumed to arise from aberrant innervation of sweat glands in the skin overlying the parotid excision. The auriculotemporal nerve carries postganglionic parasympathetic fibers that have preganglionic origins in the tympanic plexus. Sectioning of the tympanic plexus in four patients with Frey syndrome has been successful in terminating these symptoms.
Friedman WH, Pomarico JM. The Intratympanic Correction of Frey Syndrome. Arch Surg. 1974;108(3):366-368. doi:10.1001/archsurg.1974.01350270096018