At a Glance:
- Auriculotemporal syndrome is also known as Frey syndrome, Frey’s syndrome, gustatory sweating and gustatory hyperhidrosis
- Typical symptoms include excessive sweating and flushing on one side of the face along the cheek, around the ear and up to the forehead
- The condition is caused by the parasympathetic nerves that service the parotid gland (the largest salivary gland in the mouth) becoming entwined with the sympathetic auriculotemporal nerve, so a salivary response also triggers a sweating/flushing response
- Frey Syndrome is typically caused by damage to the nerves around the parotid gland. In adults this damage is typically caused by surgery to the parotid or the surrounding area. In children, the most common cause of Infantile Frey’s Syndrome is damage to the auriculotemporal nerve due to forcep delivery.
What is the Auriculotemporal Nerve?
The auriculotemporal nerve runs along the upper part of the mandible (lower jaw) and branches off from the hinge of the jaw in front of the ear. The nerve serves a number of purposes, including supplying the external acoustic meatus (ear canal), the external side of the tympanic membrane (ear drum), the auricle (the outer ear) and the temporal skin (the skin on the side of the head).
What is a Parotid Gland?
The parotid glands are the two major salivary glands in the mouth. Each person has two parotid glands - one on each side of the mouth - located at the back inside of the cheek below and in front of the ear. These glands secrete saliva to aid chewing, swallowing and digestion. In addition to being produced while chewing, salivary glands may also be activated in preparation for eating, that’s why the thought of a delicious meal may literally cause your mouth to water.
What is Frey Syndrome?
There are few people that haven’t experienced the “meat sweats” after eating a steak, or have had to mop their brow after eating a spicy curry or dish containing hot chillies. While sweating and eating is quite normal, for some people, the smell or even the thought of food may cause not only sweating but a flushing (reddening) of a line of skin on one side of their face.
First identified in 1923 by Polish physician Lucie (Lucja) Frey, Frey syndrome (Frey’s syndrome), also known as auriculotemporal syndrome, gustatory sweating, gustatory hyperhidrosis or Baillarger Syndrome is a condition that sees the areas of the head that are enervated by the auriculotemporal nerve becoming flushed due to gustatory stimulus. This stimulation is typically taste or smell, but in some cases, the thought of taste or smell, or sense memory may also trigger the response.
Auriculotemporal syndrome is caused when the auriculotemporal nerve and the parotid gland become damaged and during the healing process becomes intertwined, causing any direct stimulus to affect both the nerve and the gland instead of the nerve or the gland. As a result, gustatory stimulation that may lead to the production of saliva will also trigger a sweating/flushing response in the skin innervated by the auriculotemporal nerve.
Frey syndrome is not dangerous but for many people it can be distressing or cause emotional pain due to the highly visible nature of the flushing and sweating combined with how easily it may be triggered. The condition may affect people of any age but it is more common in adults than it is in children.
What are the Symptoms of Auriculotemporal Syndrome?
The most characteristic symptom of gustatory sweating is just that - excessive sweating, typically on one side of the face, along the jaw and cheek, around the ear and up to the forehead. This sweating may also appear in conjunction with flushing and a feeling of heat or warmth in the affected areas.
Some people complain of pain during the reaction, but it is believed that this is related to the damage that may have been done to the auriculotemporal nerve or the parotid gland rather than to Frey syndrome itself.
In children, Frey syndrome often presents as flushing without sweating. This may lead to a misdiagnosis of food allergy. Because the misdiagnosis of food allergy is so common, allergists are responsible for the diagnosis of cases of infant Frey’s syndrome.
If you or your child experience excessive sweating or flushing on one side of your face while eating, it may be a sign that you have Frey syndrome.
Schedule a consultation with your GP to have the condition properly diagnosed and treated.
The fastest and easiest way to search for and book healthcare appointments online is through MyHealth1st.
What Causes Frey Syndrome?
Frey syndrome is typically caused by damage to both the auriculotemporal nerve and the parotid gland. Normally after damage, nerves regrow along their own pathways. It is believed that in the case of gustatory sweating, the parasympathetic nerves (those related to the “rest and digest” response) and sympathetic nerves (those related to the “flight or fight” response) close to the parotid gland become damaged or cut. Instead of healing along their own pathways, researchers believe that the parasympathetic nerves instead grow along the sympathetic nerve pathway, eventually connecting to the sweat glands.
This damage may be caused by a number of different factors but the end result is the same, the nerves servicing the parotid gland and the auriculotemporal nerve becoming intertwined in some way. Possible causes of Frey syndrome include:
- Penetrating wounds in or around the parotid gland
- Heavy impact to the parotid area
- Surgery to the parotid glands (removal of cancerous tumours, parotidectomy, etc)
- Mandibular (jaw) or zygomatic (cheekbone) fractures
- Lymph node surgery to the jugulo-carotid region
- Carotid artery endocardectomy (removal of plaque from the carotid artery)
- Mandibular Temporal Joint (MTJ) surgery
- Diabetes Mellitus
- Herpes Zoster
- Central Nervous System (CNS) diseases, such as syringomyelia, Cerebrovascular Accident (CVA) or encephalitis
- Parotitis (inflammation of the salivary glands)
- Infection of the parotid glands
In children, the most common cause of Frey syndrome is due to damage done to the auriculotemporal nerve during forceps delivery. It is believed that around 50% of all cases of Infantile Frey’s syndrome are due to damage caused in this manner.
Although damage to the nerves is far and away the most common cause of Frey’s, it may take years for the nerve integration to take effect and the symptoms to show.
Treatment For Auriculotemporal Syndrome?
In most cases of gustatory hyperhidrosis, treatment is only necessary to alleviate the social stigma that may be caused by the flushing and excessive sweating it causes.
In children, Infantile Frey syndrome may spontaneously resolve, meaning that in many cases no treatment will be required. In cases where treatment is required, it may take the form of localised botulinum A (Botox) injections, laser therapy or even cosmetic treatment to hide the flushing.
In adults, treatment for auriculotemporal syndrome typically follows a number of stages, with people living with Frey’s progressing through the steps until they come to a treatment that gives lasting results.
- Stage 1 - Topical treatment. The use of topical creams or ointments to either block some response from the nervous system (anticholinergics) or those that hinder sweating (antihydrotics).
- Stage 2 - Botulinum A (Botox) injections. Botox injections have become one of the most common treatments for Frey syndrome, offering up to six months relief per injection to many people with the condition.
- Stage 3 - Surgical options. If a person living with Frey’s doesn’t respond to topical treatments or Botox injections, surgical options, such as the excision (removal) of affected skin or the implantation of an interposing layer between the parotid gland and the sympathetic nerve channels.