Somatosensory Profile Changes Evoked by Topical Application of Capsaicin to the Tongue in Healthy Individuals

Aims: To assess the effect of topical application of capsaicin to the tongue as a surrogate model of burning mouth syndrome (BMS) on somatosensory sensitivity by using a standardized battery of quantitative sensory testing (QST) in healthy volunteers. Methods: This study comprised two experimental sessions (experimental [capsaicin] and control [Vaseline]) with QST in 16 healthy women. The examiner applied capsaicin or Vaseline to the tongue tip for 5 minutes. Each participant kept their tongue tip in contact with the capsaicin/ Vaseline at the bottom of a disposable cup for 5 minutes, during which time the participant rated the perceived intensity of the tongue pain every 30 seconds on an electronic 0 to 10 visual analog scale (VAS). QST was performed on the tongue tip before and immediately after application in each session. The QST data were analyzed by two-way analysis of variance (ANOVA). Results: Mean ± standard error of the mean (SEM) of VAS pain scores during the capsaicin and control sessions were 8.2 ± 0.5 and 1.9 ± 0.2, respectively. The peak of the perceived pain in the capsaicin session was significantly higher than in the control session (P .001). In the capsaicin session, the postapplication heat pain threshold (HPT) was significantly higher than the preapplication HPT, and the postapplication cold detection threshold (CDT) and mechanical pain threshold (MPT) were significantly lower than before application (P .001). The average z scores showed a significant somatosensory loss regarding CDT. In the control session, there were no differences between preapplication and postapplication values. Conclusion: Topical application of capsaicin to the tongue tip changed somatosensory sensitivity in healthy participants. Keywords: burning mouth syndrome, capsaicin, orofacial pain, quantitative sensory testing, tongue