Gustatory sweating: clinical implications and etiologic aspects

Area of Science:

• Otolaryngology
• Neurosurgery
• Plastic Surgery

Background:

• Gustatory sweating, or Frey's syndrome, is characterized by gustatory-induced sweating and flushing in the preauricular and temporal areas.
• It is a common complication following surgery involving the parotid gland, due to aberrant regeneration of parasympathetic nerve fibers.

Purpose of the Study:

• To provide detailed clinical information on various types of gustatory sweating.
• To reevaluate patients who underwent parotidectomy, submandibular gland removal, or neck dissection.

Main Methods:

• A retrospective analysis of 548 patients' self-reported symptoms of gustatory sweating.
• Patients were categorized based on prior surgical procedures: parotidectomy (n=296), submandibular gland extirpation (n=79), and neck dissection (n=173).
• Minor's test was used to verify gustatory sweating in some cases.

Main Results:

• 45% of patients experienced gustatory sweating after parotidectomy, with symptoms typically appearing within 6 months.
• Only 1.5% of patients reported gustatory sweating after submandibular gland extirpation, and none after neck dissection.
• The "masticatory component" was identified as a significant trigger for Frey's syndrome, and symptoms were often localized to the area of parotid gland removal.

Conclusions:

• Gustatory sweating results from aberrant sympathetic or parasympathetic reinnervation of sweat glands following nerve injury.
• Misdirected parasympathetic regeneration is the primary mechanism for Frey's syndrome after parotidectomy.
• A clinically oriented classification of gustatory sweating (Types I-III) is proposed for better understanding and management.