Incidence and Characteristics of Frey's Syndrome after Parotidectomy by Minor's Starch-Iodine Test

Objectives: Frey's syndrome is an infrequent complication after parotidectomy and its incidence varies from 23.5% to 50.8% in the literature. The objective of this study was to evaluate the actual incidence and clinical characteristics of Frey's syndrome. Methods: We analyzed 31 patients who underwent parotidectomy and serial Minor's starch-iodine test. The mean follow-up period was 66 ± 26.1 months (range, 24-118 months). The Frey's syndrome was analyzed using a questionnaire for the assessment of the subjective symptom and Minor's starch-iodine test for the objective meas-urement at 1, 3, 6, and 12 months after the surgery and then every 6 or 12 months. Minor's starch-iodine test was graded from 0 to 3 according to the area of discolorization. Results: Frey's syndrome occurred in 11 patients (35.5%) on the Minor's starch-iodine test. The mean onset of Frey's syndrome on the starch-iodine test was 13.6 ± 10.4 months after parotidectomy. Sixteen patients (51.6%) complained about gustatory sweating and flushing. The onset of the subjective symptom was 11.27 ± 6.96 months after the surgery. There was a significant correlation between the grade of the starch-iodine test and the severity of subjective symptoms (P <0.001). Various factors including size and location of tumor, incision method, and extent of parotidectomy did not correlate with the Frey's syndrome. Conclusion: The incidence of Frey's syndrome was 35.5% on the Starch-Iodine test, and the onset was about postoperative 13.6 months