The Frey syndrome: a review and double blind evaluation of the topical use of a new anticholinergic agent.

The symptom complex of localized facial gustatory sweating and flushing during mastication (The Frey syndrome) is a common sequela of parotidectomy with facial nerve dissection. A thorough review of the literature concerning the Frey syndrome is reported. The procedure of tympanic neurectomy has received special emphasis with a review of 73 cases of tympanic neurectomy. The treatment modalities available, if tympanic neurectomy fails, are discussed. Important guidelines for the safe use of topical therapy to control gustatory sweating are presented as an alternative to surgical therapy. The author studied 129 post parotidectomy patients in whom 60% noted symptomatic gustatory sweating, and approximately one-fourth fo these symptomatic patients requested topical anticholinergic therapy, with one patient electing tympanic neurectomy. The only form of medical treatment presently available utilizes the topical application of scopolamine, a drug having potentially significant central nervous system side effects if systemically absorbed. In an effort to find an effective drug for topical application with a more favorable therapeutic index than scopolamine, glycopyrrolate was investigated. Glycopyrrolate was compared in varying concentrations to topical scopolamine in a personally conducted double blind clinical trial involving 16 patients. Initial results of this investigation suggest that topical glycopyrrolate in concentrations 0f 0.5% and 1.0% provide complete effective control of gustatory sweating for at least several days duration after a single application. There have been no significant side effects with the use of topical glycopyrrolate to date. Commercial topical antiperspirants were also investigated and found to be of limited benefit.