Treatment of Frey Syndrome with Botulinum Toxin-A: A Practical Approach from Minor's Test to Injection

Frey's syndrome, described by Lucy Frey in 1923, is a unique condition characterized by sweating, flushing, and reddening as a direct response to mastication. This phenomenon results from the aberrant regeneration of postganglionic parasympathetic neurons originating from the auriculotemporal nerve and the subsequent acetylcholine secretion induced by masticatory stimuli. Although rare, this syndrome can have multiple underlying causes and is frequently observed, occurring in up to 65% of cases following lateral parotid resections. Additionally, it can less commonly manifest after neck dissection, facelift procedures, or be associated with diabetes mellitus.

This article outlines a comprehensive diagnostic algorithm for Frey's syndrome, which includes the utilization of the Minor-Starch-Iodine Test. This test is a key component in diagnosing the syndrome and is discussed in detail, providing insights into its procedure and interpretation. Additionally, the gold standard of treatment for established Frey's syndrome, botulinum toxin A, is thoroughly described, including its mechanism of action, administration, and potential side effects.

Finally, the article underscores the need for further research to enhance our understanding of Frey's syndrome, leading to better diagnostic methods and more tailored treatment options for patients.