Gustatory sweating and flushing (Frey's syndrome) follows damage to the:

Auriculotemporal syndrome (Syn. Frey's Syndrome) Paial injury to the auriculotemporal nerve gives rise to such syndrome. This type of injury: May be congenital, possibly due to bih trauma. May be accidental injury. May be caused by inadverent incision for drainage of parotid abscess. May occasionally follow superficial parotidectomy. Clinical features: There is flushing and sweating of the skin innervated by the auriculotemporal nerve paicularly during meal and presence of cutaneous hyperaesthesia in front and above (the ear the area supplied by the auriculotemporal nerve.) - The postganglionic parasympathetic fibres become united to the sympathetic nerves from the superior cervical ganglion which are concerned to supply vessels and sweat glands of that region. This causes flushing and sweating of the skin. Following injury to the auriculotemporal nerve, postganglionic parasympathetic fibres from the otic ganglion grow down the sheaths of the cutaneous filaments, so hyperaesthesia follows stimulation of the secretomotor nerves. Treatment: If the symptoms persist, the treatment is avulsion of the auriculotemporal nerve in front of the auricle where it lies just posterior to the superficial temporal vessels.