Gustatory sweating: clinical implications and etiologic aspects.

PURPOSE: It was the aim of this study to provide detailed general information on the clinical picture of different kinds of gustatory sweating, including reevaluation of a series of patients who underwent parotidectomy, removal of the submandibular gland, or neck dissection.

PATIENTS AND

METHODS

This study summarizes the statements of 548 patients questioned about the occurrence of gustatory sweating after parotidectomy (n = 296), extirpation of the submandibular gland (n = 79), and neck dissection (n = 173).

RESULTS

After parotidectomy, 45% of the patients had noticed gustatory sweating. In most of them (70%), the symptoms began within 6 months after surgery. Gustatory sweating developed in only one patient with submandibular extirpation (1.5%), and not at all after neck dissection. Most patients (52%) reported that the symptoms occurred independent of the kind of food ingested. These results show that the "masticatory component" is an important trigger for Frey's syndrome. Application of Minor's test localized gustatory sweating mainly in the region of previous parotid lobe removal, but also in other areas deriving their sensory supply from the auriculotemporal, greater auricular, and lesser occipital nerves. The size of the area affected by the sweating was similar after lateral and total parotidectomy. When evaluating clinical symptoms, subjective assessment by the patients seemed to play a major role. After submandibular extirpation and neck dissection, some patients reported gustatory sweating that was not verified by Minor's test.

CONCLUSION

There is general agreement that the cause of gustatory sweating is sympathetic or parasympathetic innervation of previously denervated sweat glands, initiated by gustatory triggers. The location of the "erroneous innervation" depends on the type of lesion. In cases after parotidectomy, misdirected parasympathetic regeneration is the model integrating all known factors into a rational concept. For didactic and systematic-pragmatic reasons, a clinically oriented classification of gustatory sweating (types I to III) seems to be useful.