Frey's Syndrome - Causes

Causes

Frey's syndrome often results as a side effect of parotid gland surgery or due to injury to auricotemporal nerve. The Auriculotemporal branch of the Trigeminal 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 parasympathetic nerve fibers may switch course, resulting in "Gustatory Sweating" or sweating in the anticipation of eating, instead of the normal salivatory response. It is often seen with patients who have undergone endoscopic thoracic sympathectomy, a surgical procedure wherein part of the sympathetic trunk is cut or clamped to treat sweating of the hands or blushing. The subsequent regeneration or nerve sprouting leads to abnormal sweating and salivating. It can also include discharge from the nose when smelling certain food.