Introduction
Frey’s syndrome (syn. Auriculotemporal syndrome, gustatory sweating) is
a postoperative phenomenon following lateral parotid resection in up to
65%[1], and less commonly neck dissection or facelift procedures.
Firstly, described by Lucy Frey in 1923 it is characterized by sweating
and flushing in direct response to mastication. The mechanism is
aberrant regeneration of postganglionic parasympathetic neurons from the
auriculotemporal nerve and Acetylcholine secretion by a masticatory
stimulus. [2, 3] In Frey’s syndrome, Acetylcholine diffuses to sweat
glands in the skin and provokes sweating and/or dermal flush in the
distribution of the auriculotemporal nerve. [3] Preparation of a
thick skin flap and partial superficial parotidectomy is the most
important techniques to reduce the risk of developing a Frey syndrome.
[1] The dermal application of botulinum toxin A is an effective,
long-lasting treatment of Frey syndrome and can be repeated if recurrent
symptoms occur. [2, 4]
This article aims to list possible surgical and non-surgical treatment
options of this iatrogenic entity but should focus on the treatment with
botulinum toxin A and provide a step by step guide from the
Lugol-Iodine-Starch test to the botulinum toxin A (BoNTA-ONA) injection
within the affected area.
Even though the botulinum toxin A injection is the prevailing method of
treatment of Frey’s syndrome, some authors suggest a benefit using
dermofat grafts or special incision techniques, SMAS flaps, or the use
of facelift approaches for the parotidectomy. [5-8]