Frey syndrome affects almost all patients submitted to parotid surgery. It can mildly to severely affect the quality of life. There is no definitive treatment for it. Professor Remco de Bree from the Department of Otolaryngology / Head and Neck Surgery in Amsterdam published 2007 a clinical review about this entity. Frey Syndrome is also known as auriculotemporal syndrome or gustatory sweating. Why does it occur? What is the clinical presentation? How to avoid it? How to treat it? These are the questions the authors answer throughout the paper.
Gustatory sweating was first described by Bailllarger in 1853 after draining two parotid abscesses. It was in 1923 that Bassoe first described it following parotid surgery. Although Lucja Frey described in 1923 the role of the auriculotemporal nerve in this syndrome, it was Thomas who in 1927 presented the theory of aberrant regeneration of parasympathetic nerve fibers injured during surgery. The aberrant regeneration is responsible for the abnormal innervation of sweat glands and subcutaneous vessels. Parotid surgery is the most frequent cause of Frey syndrome.
Other causes of Frey Syndrome:
Resection of the submandibular gland
Herpes Zoster infection
Trauma by forceps
Sympathectomy
Clinical presentation affects the skin over the parotid bed while eating. Complaints include sweating (80%), erythema (40%), flush, and increased temperature (20%). Since the aberrant regeneration of parasympathetic fibers takes time, there is a latent period between surgery and the onset of Frey syndrome. According to the authors, the latency period can range from 2 weeks to 2 years, but there are reported cases of a period longer than 8 years. An interesting fact is that the affected skin area increases over time. The reported incidence varies if the patient is or is not questioned about it. If the Minor’s starch-iodine test is used, the incidence increases to 95%.
Minor’s starch-iodine test:
Cover the skin with iodine solution and let it dry
Dust the skin with starch powder
Give the patient a lemon sweet
The affected area will turn blue
There are several techniques that can be used to prevent Frey syndrome. The best technique is to decrease the area of the parotid wound bed by removing the entire disease by means of a partial superficial parotidectomy, whenever possible and indicated. A thick skin flap over the parotid is also a good way to prevent this syndrome. The interposition of barriers (musculoaponeurotic flaps, implants) are other surgical techniques available, but there is no accurate way of knowing who will benefit from them. Additionally, those barriers may only delay aberrant reinnervation and may mask local recurrences. The risk of the parotid fistula is also increased by the implants.
Quality of life can be mildly or severely affected according to a non-standard questionnaire. Social embarrassment is caused by flushing and sweating while eating. However, most patients do not require any treatment since a good explanation of the condition is satisfactory for the majority. How can we deal with this sequela? The first line treatment is the intracutaneous injection of botulin toxin A. To do it properly, the affected area must be marked with the Minor’s starch-iodine test and divided into 4 cm2 squares. Botulin toxin A is injected into the middle of each square. This technique is temporarily effective, and recurrence is high. However, it is a minimally invasive technique, the recurrent Frey syndrome is less severe than the initial one, the recurrent syndrome is responsive to another toxin administration, it is a well-tolerated treatment, and it lasts at least 6 months. For other treatment options please read the entire paper.
I want to highlight the final idea stated by Professor Remco Bree et al. – “Almost all patients who underwent parotid surgery will develop to some extent Frey syndrome, but only a minority needs treatment”. I think doctors should always ask for the Frey syndrome, but if a patient pays little to no attention to this sequela, doctors must not increase his awareness. As stated by the authors, most patients will be satisfied with a good explanation. It is important to talk to the patient and explain the procedure and possible consequences. A medical consultation cannot have a time limit. Consultations are not numbers. Surgeries are not numbers. The best department is not the one that operates more patients. The best surgeon is not the one who operates faster. The best surgeon is not the one who performs more surgeries. A hospital is not a factory that produces things. Patients are not numbers or things. Quality in medicine cannot be measured by numbers. To survive, society has to change those who are managing health services.
Link to PubMed:
Dr. Carlos Eduardo Costa Almeida
General Surgeon