Information on the following diseases can be found in the Related Disorders section of this report:

• Hyperhidrosis

In men the most obvious symptom of Frey's Syndrome is excessive sweating, while in women it is the frequency of flushing in the process of eating food. Eating hot, spicy, or very acidic food causes sweating and flushing on the cheek and ear of one side of the face. Some people may experience a temporary lack of sensitivity to heat, pain and/or burning in the affected area.

Frey's Syndrome arises from damage to the facial nerve after injury, blunt trauma to the side of the face, or as a result of surgery on or near the parotid glands. As the nerve fiber(s) regenerate, parasympathetic nerve fibers become misdirected and grow along sympathetic pathways. The parasympathetic nerves (of the autonomic nervous system) control smooth muscles such as the heart or the glands of the head and neck. Sympathetic nerves control the sweat glands. The parasympathetic nerves in the sympathetic pathways respond to a taste (gustatory) sensation by stimulating the sweat glands! The cumulative result is excessive sweating. Frey's Syndrome may occur following injury or blunt trauma to the side of the face.

Recent research suggests that certain surgical techniques to remove the parotid glands (superficial aponeurotic system preservation technique) may reduce the high risk of Frey's Syndrome in people undergoing parotid gland surgery.

Frey's Syndrome is a rare disorder that affects males and females in equal numbers.

Symptoms of the following disorders can be similar to those of Frey's Syndrome. Comparisons may be useful for a differential diagnosis:

Hyperhidrosis is a rare disorder characterized by overactivity of sweat glands. The disorder may be generalized, presenting as excessive body sweating, or localized, with sweating confined to the palms, soles, underarm areas, groin, and under the breasts. Onset of this disorder is during childhood or puberty. People with Hyperhidrosis experience a heightened reaction to agents that cause sweating (i.e., anxiety, pain, exercise, tension, caffeine, and nicotine). (For more information on this disorder, choose "Hyperhidrosis" as your search term in the Rare Disease Database.)

Frey's Syndrome can cause excessive discomfort. Treatment is symptomatic and directed toward relief of symptoms. Procaine, a local anesthetic, may be injected into the auriculotemporal nerve, which supplies the affected area of the face. Scopolamine cream, diphemanil methylsulfate, or aluminium chloride hexahydrate antiperspirants may be applied to the skin to reduce sweating. In more severe cases, surgery on the nerves near the ear and cheek may be required.

The orphan drug glycopurrolate is being developed by Robins Corporation for treatment of Frey's Syndrome.

TEXTBOOKS
Thoene JG., ed. Physicians’ Guide to Rare Diseases. Montvale, NJ: Dowden Publishing Company Inc; 1995:306

Gorlin RJ, et al., eds. Syndromes of the Head and Neck, 3rd ed. New York, NY: Oxford University Press; 1990:615-16.

JOURNAL ARTICLES
Zacherl J, et al., Video assistance reduces complcation rate of thoracoscopic sympathicotomy for hyperhydrosis. Ann Thorac Surg. 1999;68:1177-81.

Dulguerov P, et al., New objective and quantitative tests for gustatory sweating. Acta Otolaryngol (Stockh). 1999;119:599-603.

Dulguerov P, et al., Frey syndrome before Frey: the correct history. Laryngoscope. 1999;109:1471-73.

Dulguerov P, et al., Prevention of Frey syndrome during parotidectomy. Arch Otolaryngol Head Neck Surg. 1999;125:801-08.

Birch JF, et al., Botulinum toxoid in the management of gustatory sweating (Frey’s syndrome) after superficial parotidectomy. Br J Plast Surg. 1999;52:230-31.

Urman JD, et al., Diabetic gustatory sweating successfully treated with topical glycopyrrolate: report of a case and review of the literature. Arch Intern Med. 1999;159:877-78.

Cliff S, et al., Frey’s syndrome without hyperhydrosis. J R Soc Med. 1998;91:388-89.

Laskawi R, et al., Up-to-date report of botulinum toxin type A treatment in patients with gustatory sweating (Frey’s syndrome). Laryngoscope. 1998;108:381-84.