A. Case study
B. More information
C. Editors' comments
E. CPD questions (South Africa, Australia)
A. Case study
A 5-month-old boy
presented with red blotches on the left side of his face, extending
from the corner of his mouth to a little past the ear. The blotches
were not raised or swollen. The mother described the reaction as starting
close to the ear and spreading in the direction of the mouth. The "rash"
did not seem to itch or burn (the child did not try to scratch the area),
and the area was also not flaky. The rash would appear within minutes
after the child had 2 or 3 teaspoons of certain foods and would disappear
within an hour.
The mother had introduced
solid foods into her son's diet at 4 months of age. While still breastfeeding,
she started him on rice cereal, maize cereal and then commercial bottled
fruit and vegetables. This is when the rash started appearing. She decided
to discontinue the bottled food and give him fresh fruit and cooked
vegetables instead of the commercial ones. The reaction still occurred.
Food allergy was suspected.
The foods that the
boy was reacting to were commercial "Butternut," "Carrots"
and "Peaches and Apples." Also problematic were fresh mashed
banana, fresh mashed mango, cooked plain potato and cooked plain sweet
potato. He did not react to rice cereal, maize cereal, cooked plain
gem squash, ice cream, dried meat (biltong/jerky), softdrinks or rooibos
His condition was
duly distinguished from angiomas (localized vascular lesions of the
skin or subcutaneous tissues) that may be present in infants. Angiomas
are persistent red rashes or blotches, e.g., nevus flammeus (also known
as port-wine stain) and capillary hemangioma (also known as strawberry
There were many possible causes, including:
a. He was reacting to contact with the spoon, e.g., nickel allergy.
b. He was reacting to a substance that was added to the food. This could
have been among commercial additives, or it could have been any substance
(such as a flavouring) that the mother added to the food.
c. He was experiencing heat-induced urticaria, i.e., he would get a
reaction when in contact with a hot substance, in this case, food.
d. He was experiencing dermatographism (a form of urticaria in which
whealing occurs on the site and in the configuration of the application
of pressure or friction to the skin.
e. He was reacting to something else in the environment that was coincidentally
present every time he was eating.
a. The same spoon was used when giving the boy the foods that he reacted
to as the foods that he did not react to. If it was nickel allergy,
for example, the rash would be constant.
b. The food was given to the child in a pure state. Nothing was added
to it. The commercial foods did not contain any additives.
c. All foods were given at room temperature. The mother waited for cooked
foods to cool before feeding her son.
d. Dermatographism was excluded.
e. Nothing relevant could be identified.
as contact allergy, oral allergy syndrome and other physiological or
chemical causes needed to be excluded. Other questions to be asked at
a. Was he reacting to contact with the food?
b. Was he reacting to contact with a cloth, treated with a chemical,
that the mother used to wipe food off his cheek?
c. Was he experiencing any other types of reactions?
d. Was the mother giving the foods one at a time, or some together?
e. Was the reaction consistently associated with a specific food?
f. Did he ever experience a reaction at a time other than while eating?
g. Was there a relationship between the foods that he reacted to, i.e.,
a family relationship or a common allergen present?
a. When eating, the boy would get food all over his face, but the rash
would consistently appear in the same area.
b. The face cloth that was used was not treated with any chemicals and
was used on other parts of his body as well.
c. The boy did not have any symptoms other than the red blotches, such
as angioedema. He also did not complain when eating any of the food.
He was actually a good eater.
d. All foods were given one at a time, as the mother was trying to identify
a possible cause herself.
e. He reacted to most foods every time he ate them. With others, he
did not consistently experience a reaction.
f. The rash had only appeared while eating.
g. No family, allergen or chemical relationship between the foods that
affected the child could be identified.
Thus far, it could
be established that the boy reacted to foods that have no relation to
each other; that he did not react to a certain food every time; that
the only reaction he got was a rash on a specific area on his face;
that the reaction only occurred while eating; and that it did not produce
discomfort in the child.
Could it be oral allergy syndrome? This syndrome is a combination of
oral symptoms (including a swollen and itchy mouth and throat), and
a concominant sensitivity to pollen. What about allergy-associated acute
urticaria? This is also usually itchy, with raised lesions that do not
appear in the same area of the skin every time; they seem to migrate
without a fixed pattern. Also, with an allergy, one would expect the
child to react consistently to the same amount of food prepared in the
In this case, the
diagnosis was Frey's syndrome. Frey's syndrome is a disorder characterized
by recurrent episodes of localized facial flushing and/or sweating in
the area anterior to the ear and on the cheek, in response to gustatory
stimuli. The symptoms are typically unilateral. In infancy this syndrome
is a benign condition that often resolves spontaneously. Treatment is
usually unnecessary and often ineffective anyway.
What points should
have immediately diverted the health professional from suspecting food
allergy as a cause? The rash was always in the same location, occurred
in the absence of other symptoms such as edema or itching, resolved
quickly, and occurred on challenge with a variety of unrelated foods.
|TIP for Allergy
one is unsure of the type of reaction that the patient is
experiencing, the "Photos & Images" and "Glossary"
functions can be very useful. The "Photos & Images"
contains a database of photos of, amongst others, clinical
images where one will be able to compare clinical images with
the symptoms of a patient. The "Glossary" gives
descriptions of allergy related conditions and terms. In this
case, where urticaria was suspected at first, the glossary
would describe the typical presentation of urticaria as different
from what this patient experienced.
is not certain that the patient has an allergy, one can
find a list of information pieces on differential diagnosis
of allergy under the "Assessment" section of Allergy
Advisor. E.g., differential diagnosis of adverse reactions
to food, differential diagnosis of exercise induced anaphylaxis,
differential diagnosis of unexplained flushing/anaphylaxis
and the classification and diagnostic evaluation of urticaria.
B. More information:
The first case of
gustatory sweating (see below) was described in 1757 by Duphenix, but
it was not until 1923, when Lucja Frey started doing research into this
syndrome, that the term Frey's syndrome came about.1
What is Frey's
syndrome (FS) is characterized by recurrent episodes of localized
facial flushing and/or sweating in the cutaneous distribution of
the auriculotemporal nerve (i.e., the area anterior to the ear and
on the cheek).2 This usually occurs in response to gustatory
(taste) or occasionally tactile (touch) stimuli3,4,5
and usually becomes apparent within a few seconds of eating and
subsides within minutes (or longer in some cases: up to 1 hour has
been reported) after discontinuing the food.6 It has
also been termed auriculotemporal or gustatory sweating syndrome.7
The symptoms are typically unilateral,4,7 although a
couple of bilateral cases have been reported.8
This reaction, which
occurs immediately after the ingestion of food and involves a rash,
can easily be interpreted as a food allergy.3,9 It is therefore
important for health professionals to be familiar with this condition,
in particular because of our increased awareness of oral allergy syndrome
(this topic will be discussed in a future newsletter), so that unnecessary
testing and delay in diagnosis do not occur.3,4
What is the mechanism
The pathophysiology of the syndrome is not completely understood, but
there are some theories. The auriculotemporal nerve contains afferent
sensory fibers from the skin, and also contains efferent fibers, which
include secretory sympathetic fibers attached to sweat glands, sympathetic
vasodilatory fibers attached to subcutaneous vessels, and parasympathetic
vasodilatory fibers attached to the parotid gland.9 If the nerve is
injured, misdirection may occur as the regenerating fibrils join the
distal sympathetic fibers. These fibers innervate the sweat glands and
subcutaneous vessels. Subsequently, chewing may activate the sweat glands
and subcutaneous vessels instead of the fibers that carry impulses to
the salivary gland.4,10,11 In other words, as the affected person
starts eating, facial flushing and/or sweating occur instead of the
normal production of saliva from the parotid gland.12 Some patients
describe a subjective sensation of warmth in the involved area while
eating, and objective sensory deficit in the involved area is common.13
It is quite common
in adults as a result of surgery, trauma or disease of the parotid gland
area,13 but is uncommon in children. In children, FS generally presents
before the age of 1 year, and it is most commonly first noticed when
solid foods are introduced into the diet. The reason for FS not to be
associated with breastfeeding or taking formula is possibly that chewing,
particularly the more vigorous chewing of favorite foods, elicits a
more intense stimulation of the parotid gland than does the sucking
There is some evidence
suggesting that local trauma to the parotid area during delivery may
be responsible for damage to the auriculotemporal nerve in children.
About 50% of infants with FS described in the literature were delivered
with the aid of forceps. In only 7.5% of overall deliveries are forceps
used, which suggests a more than coincidental relationship. In cases
with no known trauma to the parotid area, the mechanism is thought to
be a congenital aberrant nerve pathway.2,14,16
FS has also been
described in some children with epilepsy and diverse other early childhood
diseases of the central nervous system.6
Older children may
also experience gustatory sweating, especially after suppurative parotiditis6
and accidental trauma.2 In contrast to adults and older children,
in infants and younger children it is exceptional to have sweating (they
generally only have flushing) and bilateral involvement.2,3,5,14 In
adults, gustatory sweating is the predominant feature of this syndrome,
and flushing may be associated.3
Adult FS is usually
a consequence of a parotidectomy (surgical removal of the parotid gland).
The literature has indicated that FS develops postoperatively in 13-60%
of patients undergoing paritodectomy17 and that the incidence in patients
not undergoing intraoperative preventive measures is 96%. Most patients
with FS have only mild to moderate symptoms (only 6% of patients experience
severe symptoms). FS may also occur after other surgical, traumatic
and even inflammatory injuries of the parotid or submandibular glands
and of the cervical and upper thoracic portions of the sympathetic trunk.3,4,7,16,17
FS may appear only
years after the injury.7 In most cases this interval ranges from 2
weeks to 2 years (but there has been a report of 8 years passing before
symptoms were first experienced).7 This is probably related to the
time required for nerve regeneration.3
Types of gustatory
Several gustatory sweating syndromes are described in the literature.
Gustatory sweating syndromes can be either congenital or acquired in
origin and can be either physiological or organic. Most have clearly
defined precipitating events, the commonest of which is trauma. Spontaneous
gustatory sweating syndromes have also been reported.18
The different types
identified include the following: Occurring in uniquely
hot and humid climates, of a mild degree and symmetrically distributed
over the face and neck.
trauma or inflammation of the parotid or salivary glands; i.e., auriculotemporal
or Frey's syndrome. The sweating is usually unilateral, involves the
face anterior to the ear (which is served by the auriculotemporal branch
of the facial nerve), and may be accompanied by flushing.
As a complication
of diabetic autonomic peripheral neuropathy, in which the sweating is
usually bilateral and involves the head and neck.
As a complication
of thoracic ganglionectomy (removal of the an autonomic or sensory ganglion).
brought on by one or a few specific foods such as chocolate or cheese.
The sweating is bilateral, involving the face and neck, and is often
accompanied by flushing.19,20,21
How is it treated?
Various treatments have been suggested for adults, including atropine,
antihistamines, surgical resection of the auriculotemporal nerve, botulinum
toxin, infrared thermography and scopolamine salve.4 Such treatments
have often proved ineffective and sometimes even produced significant
Although these treatments
may be effective in some adult patients, no specific therapy is recommended
for this condition in children,4 as the condition is considered to
be a benign one that often resolves spontaneously. Treatment is ineffective
||compiled by Karen du Plessis
Food & Allergy Consulting & Testing Services (FACTS)
PO Box 565
Comments by our editor
M. Joneja Ph. D., RDN
This is an excellent example of applying the first law of
food allergy practice: rule out any other pathology before considering
food allergy as the cause of the condition. Symptoms typical of
food allergy are sometimes part of a pathology that has a cause
quite distinct from adverse reactions to foods. Because so many
people - the general public as well as clinicians and health care
personnel - are very well informed about food allergy, thanks
to a significant increase in reports in medical journals and articles
in popular magazines, food allergy is often the first thing that
comes to mind when symptoms such as those discussed in this case
study are presented. However, until definitive diagnostic tests
for food allergy are available, it will tend to remain a diagnosis
of exclusion; that is, rule out any other etiological factors
first, and then consider food allergy as the cause of the patient's
For more information
on this subject and other allergy and intolerance related topics, visit:
To join a professional
food allergy discussion list where this subject can be discussed further,
go to http://groups.yahoo.com/group/AllergyDietitian
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" as the subject.
1. Hennon DK. Facial
flushing in children: a variant of the auriculo-temporal syndrome. J
Indiana Dent Assoc. 1991 Jan-Feb;70(1):25-7.
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 Mar-Apr;17(2):126-8.
3. Dizon MV, Fischer G, Jopp-McKay A, Treadwell PW, Paller AS. Localized
facial flushing in infancy. Auriculotemporal nerve (Frey) syndrome.
Arch Dermatol 1997 Sep;133(9):1143-5.
4. Karunaanthan CG, Kim HL, Kim JH. An unusual case of bilateral auriculotemporal
syndrome presenting to an allergist. Ann Allergy Asthma Immunol 2002;89:104-5.
5. Moreno-Arias GA, Grimalt R, Llusa M, Cadavid J, Otal C, Ferrando
J. Frey's syndrome. J Pediatr. 2001 Feb;138(2):294.
6. Beck SA. Auriculotemporal Syndrome Seen clinically as Food Allergy.
Pediatrics 1989; 83: 601-3.
7. Malatskey S, Rabinovich I, Fradis M, Peled M. Frey syndrome--delayed
clinical onset: a case report. Oral Surg Oral Med Oral Pathol Oral Radiol
Endod. 2002 Sep;94(3):338-40.
8. Johnson IJ, Birchall JP. Bilatral auriculotemporal syndrome in childhood.
Int J Pediatr Otorhinolaryngol 1995 Apr;32(1):83-6.
9. Sicherer SH, Sampson HA. Auriculotemporal syndrome: a masquerader
of food allergy. J Allergy Clin Immunol. 1996 Mar;97(3):851-2.
10. Du Toit DF. Auriculo-temporal nerve. Clinicopathological relevance
to facial-maxillary practice. SADJ. 2003 Mar;58(2):62-3.
11. Dunbar EM, Singer TW, Singer K, Knight H, Lanska D, Okun MS. Understanding
gustatory sweating. What have we learned from Lucja Frey and her predecessors?
Clin Auton Res. 2002 Jun;12(3):179-84.
12. Kozma C. Gustatory flushing Syndrome. Clinical Pediatrics 1993;
13. Harper KE, Spielvogel RL. Frey's syndrome. Int J Dermatol 1986;
14. Rodriguez-Serna M, Mari JI, Aliaga A. What syndrome is this? Auriculotemporal
nerve (Frey) syndrome. Pediatr Dermatol. 2000 Sep-Oct;17(5):415-6.
15. Sampson HA. Diferential diagnosis in adverse reactions to food.
J Allergy Clin Immunol 1986; 78: 212.
16. Reche Frutos M, García Ara MC, Boyano T, Díaz Pena
JM. Syndrome auriculotemporal. Allergol Immunopathol 2001; 29: 33 -
17. Teague A, Akhtar S, Phillips J. Frey's syndrome following submandibular
gland excision: an unusual postoperative complication. ORL J Otorhinolaryngol
Relat Spec. 1998 Nov-Dec;60(6):346-8.
18. Sonsale A, Sharp JF, Johnson IJ. Gustatory sweating of the external
auditory canal. J Laryngol Otol 1999 Nov;113(11):1000-1.
19. Sheehy TW. Diabetic gustatory sweating. Am J Gastroenterol 1991
20. Freeman GL. Gustatory sweating in the differential diagnosis of
food allergy. Allergy Asthma Proc. 1998 Jan-Feb;19(1):1-2.
21. Blair DI, Sagel J, Taylor I. Diabetic gustatory sweating. South
Med J. 2002 Mar;95(3):360-2.
Questions (For South African dietitians only. Australian
dietitians: where you have relevant learning goals, CPD hours related
to this resource can be included in your APD log.)
You can obtain 2 CPD points for reading
this newsletter and answering the accompanying questions. This
newsletter with questions has been accredited for dietitians.
CPD reference number: DT03/3/081/13
HOW TO EARN YOUR CPD POINTS
1. Complete your personal details below.
2. Read the newsletter and answer the questions.
3. Indicate your answers to the questions by making a "X"
in the appropriate block.
4. You will earn 2 CPD points if you answer more than 75% of the
questions correctly. If you score is between 60 and 75%, 1 CPD
point will be allocated. A score of less than 60% will unfortunately
not earn you any CPD points.
5. Make a photocopy for your own records in case your answers
do not reach us.
6. Cut and paste the area indicated below into a e-mail message
and e-mail it to firstname.lastname@example.org
to be received no later than 30 September 2003. Answer sheets
received after this date will not be processed.
ALL THE QUESTIONS
(There is only
one correct answer per question.)
1. Which of the following
is not true regarding Frey's syndrome?
(a.) It tends to occur only on one side of the face.
(b.) It can involve both flushing and sweating.
(c.) It can appear only once.
(d.) It occurs in response to gustatory stimuli.
2. True or false:
Frey's syndrome is more common in infants than in adults.
3. Frey's syndrome
can be caused by which of the following?
(a.) Surgery, trauma or disease of the parotid gland area
(b.) Surgical, traumatic or inflammatory injuries of the cervical and
upper thoracic portions of the sympathetic trunk
(c.) Delivery aided by forceps
(d.) All of the above
4. In children,
Frey's syndrome generally presents before what age?
(a.) 1 year
(b.) 4 months
(c.) 6 months
(d.) 10 years
5. True or false:
Infants and younger children with Frey's syndrome generally only have
flushing, compared to adults, in whom gustatory sweating is the predominant
6. The literature
has indicated that Frey's syndrome develops postoperatively in which
percentage of patients undergoing paritodectomy without intraoperative
7. True or false:
Frey's syndorme may appear only years after the injury.
8. Which of the
following is true regarding the treatment of Frey's syndrome?
(a.) It is very effective in adults.
(b.) It is very effective in children.
(c.) No side effects have been reported.
(d.) No specific therapy is recommended for children.
Cut and paste
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HPCSA number: DT
Surname as registered with the HPCSA:
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