Frey's syndrome: treatment with topical glycopyrrolate

Gustatory sweating and flushing of the facial skin, or Frey's syndrome, is fairly common after parotidectomy. The most likely mechanism is aberrant reinnervation of the sweat glands of the face by the severed parotid parasympathetic nerve fibers. A survey of 61 patients having undergone parotidectomy yielded 29 (47.5%) with gustatory sweating. Twenty-three percent (14 patients) considered the symptoms severe. In a double-blind study, five of those 14 patients were alternately treated with topically applied placebo and with glycopyrrolate (an anticholinergic agent) as 0.5% lotion, 2% lotion, and 2% cream. All five patients showed some improvement with the test preparations, but had longer lasting and more effective lessening of symptoms with the 2% glycopyrrolate preparations. There were no adverse side effects. We therefore believe that the topical application of a 2% glycopyrrolate preparation is a safe and effective treatment for severe gustatory sweating following parotidectomy.