What is Frey Syndrome?
Frey syndrome, also known by several other names (like Baillarger’s syndrome, auriculotemporal syndrome or Dupuy syndrome), happens when the auriculotemporal nerve in your face is damaged. This nerve helps start the production of saliva and also controls sweat glands on the face and scalp. If the nerve is injured, it can regenerate in an unusual way, leading to Frey syndrome. This normally happens after a person has had an injury or surgery in the parotid region (where the saliva glands are located).
People with Frey syndrome may feel hotness, flushing or sweating on the side of the face where the parotid gland is located. This is often more noticeable when eating, especially spicy or sour foods. In most cases, Frey syndrome arises after a type of surgery known as parotidectomy (removal of the parotid gland). However, it can also occur after other surgeries, injuries or infections in the parotid region.
The symptoms of Frey syndrome were first observed in 1853 by Dr. Jules Baillarger. He saw this in two patients who had had surgery for parotid gland abscesses. They later went on to develop facial sweating while eating. At that point, he mistakenly thought the sweating was because of a blocked salivary duct. Years later in 1897, a patient who had had the same parotid surgery was reported to have sweating and flushing on both sides of the face, which was named as bilateral Frey syndrome.
The syndrome was only accurately described in 1923 by Dr. Lucja Frey. She linked the syndrome to autonomic nerves (nerves that control body functions we don’t consciously control, such as heart rate, digestion, and sweating), specifically the auriculotemporal nerve, which when stimulated during eating can lead to facial sweating. Then, in 1927, Dr. Andre Thomas proposed that the cause of the disease was due to unusual nerve regeneration. Dr. Peter Bassoe, in 1932, reported the first case of Frey syndrome after parotidectomy, which is now known as the most common cause of the condition.
What Causes Frey Syndrome?
Frey syndrome typically happens in adults who have had an injury to the auriculotemporal nerve, a nerve near the ear, due to surgery or trauma in a region called the parotid.
This nerve is made up of two parts. The upper part, which comes from a large nerve in the face, the trigeminal nerve, provides sensation to areas like the ear, jaw joint, and the side of the head. The lower part comes from the glossopharyngeal nerve and controls the actions of the parotid gland, which produces saliva.
Once these two parts come together, the nerve travels at the back of the jaw and parotid, giving off a branch responsible for saliva production. If this nerve is injured either near to or at this branch, Frey syndrome can occur. In some rare cases, symptoms have been seen on the side of the head, even if the injury is closer to the ear.
Salivary gland tumours, which represent a small percentage of all head and neck tumours, are a frequent cause of Frey syndrome because they often necessitate a parotidectomy, which is the removal of the parotid gland. This procedure is the most common cause of Frey syndrome in adults, and it also comes with other complications, such as facial paralysis, scars, and discomfort. Larger tumours, which require a more extensive surgery, increase the risk for Frey syndrome due to increased exposure and potential damage to the parasympathetic nerves, which control actions like saliva production.
In addition to parotidectomy, Frey syndrome can also be caused by trauma to the parotid region, fractures of the jaw or jaw joint, infections, as well as removal of other glands.
Frey Syndrome isn’t as common in children, and can sometimes occur in early infancy without a history of trauma or surgery. It’s often confused with food allergies because the symptoms start around the same time that a child starts trying new foods. However, it can be distinguished from allergies by a quick onset after a meal, occurrence with specific foods, rapid recovery without treatment, and absence of other allergy symptoms. In these cases, the nerve is often crushed rather than cut, reducing symptoms and sometimes allowing for recovery.
In the rare case where symptoms are seen on both sides, it’s likely due to an unknown cause, potentially an inborn dysfunction of the auriculotemporal nerve.
Risk Factors and Frequency for Frey Syndrome
Frey syndrome, which can happen after a specific type of head and neck surgery called a parotidectomy, has been reported to occur in anywhere from 4% to 96% of patients. This range is quite broad due to differences in how severely patients experience symptoms, how they report them, and how doctors diagnose the condition.
Tests reveal that about 80% of patients who have had a parotidectomy might develop Frey syndrome. However, when relying on patient’s descriptions of their own symptoms, the rate goes down to between 30% and 60%. This suggests that many people who have Frey syndrome may not show any symptoms, or their symptoms don’t bother them that much.
It’s also important to note that anyone, regardless of their age or gender, is susceptible to developing Frey syndrome. It doesn’t seem to affect certain groups more than others.
Signs and Symptoms of Frey Syndrome
Frey syndrome is a condition that commonly affects individuals who’ve had surgery or trauma in the area around the ears, known as the parotid region. However, it can also start without any clear cause and can even be present in infants. The main signs of this syndrome include sweating, redness, nerve pain, itchiness, and warmth on one side of the face and close to the area of your ears, most commonly after eating sour or spicy foods. Depending on the person, these symptoms can range from barely significant to mildly bothering. In some cases, they can even lead to social anxiety and avoidance of eating in public. Symptoms can start to show weeks, months, or even years after the initial trigger. Physical signs may include signs of past surgery or injury in the parotid region.
- History of surgery or trauma around the ears
- Unilateral (one-sided) facial symptoms such as sweating, redness, nerve pain, itchiness, and warmth
- Symptoms usually triggered by eating sour or spicy foods
- Severity of symptoms can vary from non-bothersome to mild annoyance, and in severe cases, social anxiety and avoiding eating in public
- Symptoms can appear weeks, months, or even years after the initial trigger
- Physical examination may show signs of previous surgical intervention or trauma in the ear area
Testing for Frey Syndrome
Before, Frey syndrome was diagnosed based purely on the symptoms reported by patients. Nowadays, there are more reliable tests to confirm this condition, one of them being the Minor starch-iodine test.
During this test, the area of the face affected by the condition is coated with iodine. After it has dried, starch is then applied on the iodine-coated area. The person is then given something that would usually make them salivate, like a sour candy. If Frey syndrome is present, the activation of their sweat glands will cause the starch to get wet and change its color to blue/brown due to the presence of iodine.
Treatment Options for Frey Syndrome
Frey syndrome is a condition that can cause excessive sweating and flushing around the face. It typically develops after surgery in certain areas of the head and neck. There are several approaches doctors use to prevent it from occurring after surgery but all of these techniques come with their own risks and complications.
One technique involves thickening the layer of skin, fat, and connective tissue (the skin flap) over the salivary gland during the surgery. This added thickness could potentially shield the nerves that control sweating from being exposed to the regenerating nerves in the surgical area. While this strategy hasn’t been found to significantly decrease the occurrence of Frey syndrome, it might reduce the overall severity of the condition.
Another method involves the use of an acellular dermal matrix (ADM), a type of graft that acts as a biological barrier between the salivary gland and the overlying skin. Although some studies have shown mixed results, the use of ADM has been found to reduce the occurrence and the symptoms of Frey syndrome significantly.
Doctors may also use a technique called autologous fat implantation, which uses the patient’s own fat to improve the shape and appearance of the surgical area. However, this technique may lead to complications such as bruising, infection, and fluid collection at the site where the fat was taken.
Specific surgical procedures like the superficial muscular aponeurotic system (SMAS) flap technique also help prevent Frey syndrome. This technique uses a layer of tissue that works with the facial muscles to protect the facial nerve. The flap of tissue is then tightly sutured to the skin near the ear and to a neck muscle referred to as the sternocleidomastoid muscle. This procedure may also help improve the look of the surgical area. Some studies have shown this technique helps reduce the severity of Frey syndrome and the area of the skin affected.
There are other surgical techniques which involve the use of tissue flaps from the temporoparietal fascia (TPF) or the sternocleidomastoid muscle (SCM), but they come with additional potential risks such as increased surgical time and potential nerve damage.
Drugs that inhibit excessive sweating (known as anticholinergic drugs) are also used to treat Frey syndrome. These include atropine, scopolamine, and glycopyrrolate. Topical antiperspirants are generally not very successful in controlling the sweating associated with this condition. Other drugs like botulinum toxin are injected into the affected area and have proven very effective, but the benefits usually diminish over time and repeat injections are often necessary.
Surgery to manage Frey syndrome is rarely performed and is usually reserved for occasions when other treatments are no longer effective. Surgical interventions mainly focus on disrupting the nerves associated with the sweating response, inserting a barrier to prevent nerve regeneration, or removing the affected skin. However, all of these surgical procedures come with their own risks and potential complications.
What else can Frey Syndrome be?
Frey syndrome can be mistaken for food allergies in children. This confusion usually happens in early infancy, during the introduction of different foods in the child’s diet. However, differences in the two conditions exist. Frey syndrome symptoms start soon after eating, do not respond to allergy treatment, are triggered by specific types of food (like sour and sweet), affect only the parotid region, and do not involve other allergy symptoms. If the child had any medical procedure during delivery, doctors may also suspect Frey syndrome.
Primary hyperhidrosis is a condition where a person sweats excessively. It affects about 0.6 to 1% of people. Most of the times, we don’t know the cause. But those affected often have these experiences for at least six months: sweating often and symmetrically, excessive sweating starts when they are under 25 years old, family history of the condition, and lack of sweating during sleep. Secondary hyperhidrosis can be caused by various conditions: taking certain drugs, exposure to toxins, thyroid, pituitary or metabolic disorders, cancer, some brain disorders, or inherited conditions such as Riley-Day syndrome.
Emotional sweating is triggered by emotions and primarily affects the palms and soles. Sometimes the armpits are also involved. It does not happen while the patient is sleeping or under sedation. Compensatory hyperhidrosis is typically a side effect of surgery to the chest region of the spinal cord (thoracic sympathectomy), used to treat primary hyperhidrosis. This procedure can disturb the body’s natural system for controlling body temperature, leading to uncontrollable sweating in areas not treated by the surgery, usually below the level of the operation.
Gustatory tearing or “crocodile tears” is another condition where there is unilateral tearing in response to taste stimuli. This is commonly seen after healing from facial paralysis, Duane syndrome, and trauma. It is believed to stem from abnormal nerve healing of facial and glossopharyngeal nerves causing these nerves to stimulate tear production. Treatments for this condition are varied and can range from minor surgery to the lacrimal gland (which produces tears), using anticholinergic medications (drugs affecting nerve communication), cutting specific nerves, injecting alcohol into a group of nerve cells located in the face, or injecting botulinum toxin into the lacrimal gland.
Gustatory rhinorrhea is caused by a similar nerve issue as gustatory tearing. After physical damage, nerves that originally went to the parotid gland heal improperly and instead go to a nerve that affects the glands of the nasal and palatine mucosa. This results in one-sided nasal discharge when the person eats.
First bite syndrome is another nerve injury syndrome where nerve damage prevents normal control of cells that contract in response to taste, which can cause pain with eating and drinking. The pain is typically most noticeable at the beginning of a meal and fades quickly after that. First bite syndrome is most commonly seen following surgery to glands near the mouth and throat, but may also occur following surgery on a blood vessel in the neck (carotid endarterectomy) and face lifting.
What to expect with Frey Syndrome
Frey syndrome is a harmless condition that usually remains stable once it develops. Patients who show no symptoms are rarely treated and are mostly studied for research purposes. However, most patients who do exhibit symptoms can be effectively managed with simple treatments. These include the use of antiperspirants, medications that reduce bodily secretions (anticholinergics), and botulinum toxin.
For those with more severe or persistent cases, surgery can provide a solution. In children, more than half of those who have symptoms on one side see these symptoms disappear naturally. In cases where both sides are affected, which is not usually related to birth injuries, the symptoms resolve in just over half of patients during their first year.
Possible Complications When Diagnosed with Frey Syndrome
Frey syndrome doesn’t cause any major health issues; however, it can negatively impact a person’s quality of life. The discomfort and personal perception of Frey syndrome can linger for more than five years after surgery. Surveys about quality of life have found a significant link between poor social functioning, financial trouble, speech issues, decreased sexual drive, poor oral nutrition, and Frey syndrome.
Common Issues:
- Poor social functioning
- Financial troubles
- Speech problems
- Decreased sexual activity
- Poor oral nutrition
- Lasting discomfort even five years post-surgery
Preventing Frey Syndrome
Frey syndrome, though often considered a minor complication, can be overlooked by surgeons and greatly impact the patient’s well-being. It’s been noticed that many patients don’t remember being properly educated about the chances of experiencing Frey syndrome after parotid surgery – a procedure involving the salivary glands. It’s critical that before the surgery, patients are well-informed about the possibility of Frey syndrome, so they’re prepared and can identify the symptoms early. This helps in getting timely diagnosis and treatment, and to set realistic expectations for recovery period. If, after the surgery, the patient experiences symptoms like facial warmth, flushing, and excessive sweating when eating acidic or spicy food, it’s crucial to let the surgeon know.
We shouldn’t forget the social impact of Frey syndrome either. Surveyed patients who underwent parotid surgery due to benign—non-cancerous—salivary gland diseases, often reported gustatory sweating (sweating during eating) as their most severe issue. This complication led to decreases in their quality of life, discomfort during meals, and an overall increase in discomfort over time. By ensuring patients are educated early on, correctly diagnosed, and treated promptly, the linked social issues can be better managed and reduced.