[Effectiveness of botulinum toxin A in the treatment of gustatory sweating]

Frey's syndrome is present in almost all patients after parotidectomy. Gustatory sweating reduces quality of life. Injections of botulinum toxin A have recently been described as effective. This study was designed to evaluate the efficacy of this new treatment. Nineteen patients with severe gustatory sweating following superficial parotidectomy were treated. One unit/cm2 botulinum toxin A was injected intracutaneously into the affected area once. Minor's starch iodine test was performed to prove the outcome of therapy 4 weeks later. Eight patients lost their sweating. However, another seven patients had some blue spots on their cheeks. In four patients whose sweating had extended beyond the hairline, remnants of gustatory sweating showed up. Overall, the affected area of gustatory sweating could be reduced by botulinum toxin A from an average of 31 cm2 before treatment to 4 cm2 after treatment. Although there were some remnants of sweating in a few patients, Frey's syndrome was gone in all cases. No side effects could be observed. Intracutaneous injections of botulinum toxin A are highly effective and safe in treatment of gustatory sweating.