Background: In Prey's syndrome, the secretory parasympathetic fibers o
f the parotid gland are thought to communicate with the sympathetic ne
rve fibers of sweat glands and blood vessels of the skin following par
otidectomy. Miscommunication results in subjective gustatory sweating
and facial flushing, which appear early with postoperative mastication
. In this study, we compared the efficacy of medical thermography to t
he Minor's starch-iodine test to determine the presence of gustatory s
weating in Prey's syndrome. Methods: Patients were considered to have
Prey's syndrome if signs of gustatory sweating and localized skin flus
hing of the parotid region were present. In four patients who had unde
rgone unilateral parotidectomy, gustatory sweating and facial flushing
were present after gustatory stimulation, and the presence of Prey's
syndrome was confirmed with Minor's starch test in all patients. Infra
red thermography was then performed, and the same area measured. The c
ontralateral side served as an internal control for each patient. Resu
lts: Before gustatory stimulation, the isothermal pattern of the disea
sed side and the nonoperative side was similar. Stress thermography us
ing a sialogogue (lemon, 3 mt) showed a cold spot at the operative sit
e in all four patients with Prey's syndrome. The contralateral nonoper
ative side showed normal skin temperature distribution in all patients
. Minor's test was positive in all patients. Conclusions: Thermography
is a noninvasive, facile test that provides a qualitative visual anal
ysis of the cutaneous capillary response in Prey's syndrome following
parotid surgery. (C) 1997 John Wiley & Sons, Inc.