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]