ABSTRACT
BACKGROUND: Frey's syndrome (FS) is defined as facial sweating due to gustatory stimuli following surgery or trauma of the parotid gland. Concomitant symptoms may occur in the area of the auriculotemporal nerve: swelling, facial flushing, and paresthesia. A misguided re-innervation of perspiratory glands by secretory parasympathetic fibres is likely responsible in the pathogenesis. The reported incidence in the literature varies considerably from 1.7% to 97.6%. The present study aims to clarify the incidence of FS. PATIENTS AND METHODS: A questionnaire was sent to 221 consecutive patients who underwent parotidectomy between 07/2005 and 07/2008. No selection for type of parotidectomy or histological result was made. Patients were invited to undergo a follow-up examination including Minor's iodine starch test. RESULTS: A total of 135 of 221 (61%) questionnaires were available for evaluation. In all, 82 patients took part in the follow-up, with a follow-up period of 2.8 years (15-51 months). According to the questionnaire, 54% of patients claimed to be free of symptoms. Sweating following gustatory stimuli was reported by 23% of patients. Of the 82 Minor's tests performed, 62.2% were positive. All patients with subjective presence of FS had a positive Minor's test. In 27%, Minor's test was positive although patients did not suffer from facial sweating subjectively ("subclinical FS"). In all, 39% had no subjective complaints and Minor's test was also negative. Cases with a positive Minor's test showed no statistically significant relation to the patients' age, gender or to the histological diagnosis or type of parotidectomy. CONCLUSION: The clinical incidence of FS in our study is 23%, although a positive Minor's iodine starch test was observed in 62% of cases. Therefore, it seems justifiable to differentiate between a symptomatic or clinical FS and a merely asymptomatic or subclinical FS. No correlation was observed between epidemiological factors and the occurrence of FS.
