Topical capsaicin application and axon reflex vasodilatation of the tongue: Neurogenic involvement in burning mouth syndrome.

The aim of this study was to evaluate the effects of topical capsaicin application on human lingual mucosa and to assess if neurogenic inflammation might have a role in the pathogenesis of lingual diseases. Thirty patients (16 males and 14 females; mean age: 41.46 +/- 11.8 years; range: 23-60) were examined in our laboratory. The neurogenic inflammation was experimentally induced in the lingual mucosa close to 1) the left margin of the tongue and 2) the right margin of the tongue after ipsilateral nerve trunk anesthesia. The characteristics of lingual microcirculation were observed using computerized videocapillaroscopic techniques. The vasodilatation was observed close to the left margin of the tongue, and an important correlation was observed between capsaicin application and capillary tortuosity. No significant modifications in vascular diameter and tortuosity were observed after capsaicin application close to the right margin of the tongue. The results of the present study are of interest, in particular, in regard to recent studies pointing to neurogenic involvement in oral diseases such as burning mouth syndrome.