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Journal of Indian Society of Pedodontics and Preventive Dentistry Official publication of Indian Society of Pedodontics and Preventive Dentistry
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Year : 2019  |  Volume : 37  |  Issue : 4  |  Page : 414-416

Auriculotemporal nerve syndrome (Frey's syndrome): A literature review and case report

Department of Pediatric Dentistry, The Hebrew University-Hadassah School of Dental Medicine, Jerusalem, Israel

Date of Web Publication7-Nov-2019

Correspondence Address:
Dr. Roy Petel
The Hebrew University-Hadassah School of Dental Medicine, Jerusalem
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/JISPPD.JISPPD_285_18

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Frey's syndrome in children is rare and often erroneously attributed to food allergy. A description of a case of Frey's syndrome in a child and a review of the literature is provided. Awareness of this condition is important for the pediatric dentist to avoid unnecessary medical procedures and provide reassurance to the dental team in the setting of this benign condition.

Keywords: Auriculotemporal nerve, erythema, gustatory sweating, unilateral or bilateral flushing

How to cite this article:
Petel R. Auriculotemporal nerve syndrome (Frey's syndrome): A literature review and case report. J Indian Soc Pedod Prev Dent 2019;37:414-6

How to cite this URL:
Petel R. Auriculotemporal nerve syndrome (Frey's syndrome): A literature review and case report. J Indian Soc Pedod Prev Dent [serial online] 2019 [cited 2023 Jan 27];37:414-6. Available from: http://www.jisppd.com/text.asp?2019/37/4/414/270480

   Introduction Top

Frey's syndrome is a well-known phenomenon in adults. It is a common postoperative complication of parotid gland surgery, manifested as sweating and/or dermal flushing during salivary stimulation.[1] In the pediatric population, however, it is rare and often misdiagnosed as allergy, prompting unnecessary diagnostic testing and treatment.[2] In infants, Frey's syndrome is thought to result from perinatal trauma to parasympathetic branches of the auriculotemporal nerve associated with forceps assistance at the time of delivery.[3]

Here is a description of a case of Frey's syndrome in a child during dental treatment and related review of the literature. Awareness of this condition is important for the pediatric dentist to avoid unnecessary medical procedures and provide reassurance to the dental team in the setting of this benign condition.

   Case Report Top

An otherwise healthy 5-year-old Caucasian boy with unremarkable medical history presented to a private dental clinic for routine dental care. Oral examination revealed a normal complement of teeth for his age with one carious lesion. This was his first visit to a dental clinic.

The treatment plan included a restoration of the right primary first molar, some sealants, and dental hygiene procedure with application of fluoride varnish under inhalation sedation of nitrous oxide.

On the day of the appointment, the child arrived with his father and was seated in the chair with his father sitting next to him. After induction of nitrous oxide, an infiltration of lidocaine 2% with 1:100,000 epinephrine local anesthesia was administered (1.8cc of 2% lidocaine with epinephrine 1:100,000 by infiltration) and dental treatment commenced as planned. Under rubber dam (Henry Schein INC, Melville, USA), a carious molar was restored using Glass Ionomer (Equia, GC, Tokyo, JAPAN), and then, sealants were applied using 3M™ Clinpro™ Sealant (St. Paul, MN, USA). After removing the rubber dam, a thorough cleaning of the teeth was initiated using 3M™ Clinpro™ Prophy Paste (St. Paul, MN, USA). Approximately, 5 min after the initiation of the dental hygiene procedure treatment and 20 min after initiation of the whole treatment, a redness appeared on the right cheek of the child with no other signs or symptoms [Figure 1]. The treatment was stopped and the child was monitored. The redness disappeared in less than 45 min. The father mentioned several events with “rashes” in the past while feeding the child as a baby and several times after the child consumed sour candies or spicy foods and said that the pediatrician had diagnosed those events as gustatory flushings. The father did not report of any test done to confirm the diagnosis such as Minor's iodine-starch test, as the redness after chewing and consuming fruits or drinking sour or sweet beverages was typical for that condition according to their pediatrician. The father also reported that the delivery of the child was with forceps assistance, which possibly caused trauma to the nerve as the doctors explained to him later. He did not consider this information noteworthy to indicate on the medical questionnaire before the dental treatment.
Figure 1: The image shows the redness that appeared on the child's right cheek 5 min after initiation of dental prophylaxis

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   Discussion Top

Flushing is often a manifestation of a benign condition; in some cases, it may be the first sign of a more serious disorder and specific diagnostic tests are needed to rule out these diseases. Flushing can be produced by agents acting on the vascular smooth muscle receptors or by signals sent by the vasomotor nerves. It can be episodic or persistent. Episodic flushing is usually caused by endogenous vasoactive mediators or medication. Persistent flushing is caused by successive episodes over long periods, which eventually leads to the appearance of telangiectasias and enlarged vessels with slow-flowing deoxygenated blood.[4]

[Table 1] shows the differential diagnosis for facial flushing [4],[5] in children and young adults.
Table 1: Differential diagnosis for facial flushing in children and young adults[4],[5]

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Auriculotemporal nerve syndrome usually manifests as immediate unilateral or bilateral flushing, sweating in the distribution of the auriculotemporal nerve, or both in response to gustatory or tactile stimuli. In adults, this syndrome is a well-recognized sequela of parotid surgery, trauma, or infection. It occurs rarely in children, most often noted after the introduction of solid food. The flushing is often attributed erroneously to food allergy. It typically begins at 2–6 months of age when solid foods, mostly fruit, are introduced. Occurring within a few seconds of eating, it has a peculiar distribution in a triangular area that extends from the tragus of the ear to the midpoint of the cheek. It is not associated with sweating and persists for 20–60 min. The flushing continues to occur for up to 5 years. In adults, gustatory sweating is the predominant feature of auriculotemporal nerve syndrome; flushing happens less often. One half of pediatric patients with this symptom were delivered with forceps assistance, which possibly causes trauma to the nerve. The likely mechanism is misdirection of parasympathetic fibers along sympathetic pathways during the nerve regeneration that follows trauma. This may account for erythema when eating. The emergence of symptoms several months after the proposed trauma (usually 3–6 months) is probably related to the time required for nerve regeneration, and it is possible that vigorous chewing causes intense stimulation of the parotid gland. Auriculotemporal nerve syndrome is benign in infants and does not tend to worsen. Furthermore, the severity of the flushing tends to diminish with age in most patients. In 1928, a qualitative test of sudomotor function [6],[7] was demonstrated by Victor Minor – The Minor's iodine starch test. It is also useful in establishing the diagnosis of Frey's syndrome. A solution of commercially available tincture iodine which is an alcohol-based weak iodine solution containing elemental iodine along with sodium or potassium iodide is used. A layer of this solution is painted on the patient's forehead and allowed to dry. The forehead is then dusted with a thin film of starch, such as corn flour. Otherwise healthy controls may be asked to perform mild exercises to encourage sweating. Within minutes, as the sweat comes in contact with the starch iodine mixture, the color changes from white to a dark blue-black, allowing sweat production to be visualized easily. Complete color change occurs within 20–30 min. There is no color change on the affected side.

If an allergic reaction is suspected, the patient should be referred to an immunologist. The immunologist would consider measurement of immunoglobulin E level and perform a skin prick test for a specific substance.

When the findings do not clearly support a particular diagnosis, the next step should be to investigate the less common causes, such as anxiety, psychiatric disorders, idiopathic flushing, and mast cell activation syndrome.[5]

   Conclusion Top

Awareness of this condition by the pediatric dentist and dental team is important to avoid unnecessary medical procedures and provide reassurance to the dental team.

However, if the condition was not diagnosed before, it is important to rule out an allergic response or other causes.

The condition mimics other flushing syndromes including allergy that a pediatric dentist should be well aware of.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

Johnson J, Newlands S, Bailey B. Head and Neck Surgery – Otolaryngology. 4th ed. USA: Williams & Wilkins, Lippincott; 2006.  Back to cited text no. 1
Giovannini-Chami L, Blanc S, Albertini M, Bourrier T. Frey's syndrome: Differential diagnosis of food allergy. Arch Dis Child 2014;99:457.  Back to cited text no. 2
Kaddu S, Smolle J, Komericki P, Kerl H. Auriculotemporal (Frey) syndrome in late childhood: An unusual variant presenting as gustatory flushing mimicking food allergy. Pediatr Dermatol 2000;17:126-8.  Back to cited text no. 3
Izikson L, English JC 3rd, Zirwas MJ. The flushing patient: Differential diagnosis, workup, and treatment. J Am Acad Dermatol 2006;55:193-208.  Back to cited text no. 4
Lafont E, Sokol H, Sarre-Annweiler ME, Lecornet-Sokol E, Barete S, Hermine O. Causes and differential diagnosis of flush. Rev Med Interne 2014;35:303-9.  Back to cited text no. 5
Minor V. Ein neues verfahren zu der klinischen untersuchung der schweissabsonderung. Dtsch Z Nervenkr 1927;101:302.  Back to cited text no. 6
Choi HG, Kwon SY, Won JY, Yoo SW, Lee MG, Kim SW, et al. Comparisons of three indicators for Frey's syndrome: Subjective symptoms, minor's starch iodine test, and infrared thermography. Clin Exp Otorhinolaryngol 2013;6:249-53.  Back to cited text no. 7


  [Figure 1]

  [Table 1]

This article has been cited by
1 Auriculotemporal Frey syndrome not associated with surgery or diabetes: systematic review
Céline Betti, Gregorio P. Milani, Sebastiano A. G. Lava, Mario G. Bianchetti, Gabriel Bronz, Gian P. Ramelli, Barbara Goeggel Simonetti, Marcel M. Bergmann
European Journal of Pediatrics. 2022;
[Pubmed] | [DOI]
2 Case for diagnosis. A transient unilateral face rash upon eating: Frey syndrome
Ana Gusmão Palmeiro, Laura Azurara, Bernardo Pimentel, Cristina Amaro
Anais Brasileiros de Dermatologia. 2022;
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