Hello, I can understand your concern. What you are describing is a typical symptom of Frey s syndrome. It is a rare disorder, but as the doctors have ruled out all other pathologies and you are still experiencing the problem, I am suggesting it. Frey s syndrome happens when a specific nerve, called Auriculotemporal nerve which passes through the parotid gland (salivary gland) gets damaged. As the nerve is related with producing sweating and the parotid gland is related with producing saliva while eating. Thus, when parotid gland is stimulated to produce saliva, sweating occurs. I would advise you to visit an oral or neurosurgeon for examination and a specific test called Starch Iodine Test to confirm the presence of the disorder. If it is indeed the cause of your problem, you can be prescribed an ointment to apply over the area or can be given injection of Botulinum Toxin A in the nerve. I hope this information helps. Thank you for choosing HealthcareMagic. I wish you feel better soon. Best, Dr. Viraj Shah