Frey's syndrome (also known as Baillarger’s syndrome, Dupuy’s syndrome or Frey-Baillarger syndrome) is a food related syndrome which can be congenital or not, and can persist for life.
The symptoms of Frey's syndrome are redness and sweating on the cheek area adjacent to the ear. They can appear when the affected person eats, sees, thinks about or talks about certain kinds of food which produce strong salivation. Observing sweating in the region after eating a lemon wedge may be diagnostic.
Frey's syndrome often results as a side effect of parotid gland surgery. The Auriculotemporal branch of the Mandibular nerve carries sympathetic fibers to the sweat glands of the scalp and parasympathetic fibers to the parotid gland. As a result of severance and inappropriate regeneration, the fibers may switch courses, resulting in sweating in the anticipation of eating, instead of the normal salivatory response.