Clinical results in the management of Frey's syndrome with injections of Botulinum toxin.

Introduction: Frey's Syndrome is defined by facial hyperhidrosis in the preauricular region unleashed by gustatory stimulus and caused mainly by parotidectomy. Several treatment and prevention measures have been proposed, with no conclusive results. Recently, injections of Botulinum Toxin have been suggested, obtaining encouraging results. The objective is to describe our experience in treating Frey's Syndrome with this drug.

Materials And Method: Between 2004 and 2007, our team treated 10 patients suffering from Frey's Syndrome. All cases were caused by parotid resection. In 60%of cases a complete elevation of the SMAS (superficial musculoaponeurotic system) was carried out. In the remaining cases, such elevation was either not made or the SMAS was severely damaged. All patients were treated with intradermic injections of Botulinum Toxin. Recorded data were: units administered, affected area, time lapse until improvement in the symptoms, and the evolution after one, six and twelve months after the injection. Possible side effects were also recorded.

Results: The average treated area per patient was 26 cm2. An average of 38 units of Botulinum Toxin per patient was injected. Average time lapse until improvement was 5.5 days. Five patients were injected with a second dose after an average of 18 months from the first injection. On this occasion, the area affected was considerably smaller than that presented before the first injection. The most frequently reported side effect was dry mouth.

Conclusion: Our team considers that treating Frey's Syndrome with Botulinum Toxin is effective. The effects of the treatment are long-lasting and side effects are minimal and temporary. A second injection is needed after 15 to 18 months of the first, although the affected area is usually smaller.