2019 Volume 65 Issue 8 Pages 500-506
Glossodynia is defined as a burning sensation on the tongue without any systemic or local cause. Although its pathophysiology remains unclear, it has been associated with neuropathic, nociceptive, and psychogenic pains. In Japan, difficulties are encountered in the treatment of glossodynia as prescribed medications are not covered by health insurance. Recently, a traditional Chinese medicine treatment (kampo), rikko-san (TJ-110), has been suggested to be useful for glossodynia. The objective of this retrospective study was to evaluate the efficacy of rikko-san gargling in patients with glossodynia. In total, 221 patients with glossodynia who were treated by rikko-san gargling between 2012 and 2018 were examined. Of these, 90 patients (seven men, 83 women; mean age, 67 years) who were treated by gargling with rikko-san dissolved in water for >1 month and no other medications were included. Tongue pain was assessed using a visual analog scale (VAS). Improvement was defined as at least a 50% reduction in the VAS score after treatment compared with that before treatment. The associations between the efficacy of rikko-san gargling and factors such as age, disease duration, pain area, and psychiatric disorders were evaluated. Improvement was noted in 60% of the patients (54/90) ; the mean administration period to the end of treatment in the improvement group was approximately 5 months. There was no significant correlation between the aforementioned factors and the efficacy of rikko-san gargling. Treatment in 41 patients was completed with rikko-san gargling alone, whereas 40 patients required additional treatment such as another kampo medicine or ethyl loflazepate. No side effect was observed in any patient, although stomatitis was noted in one excluded case.
The mechanism underlying rikko-san’s delivery pathway is distinct from that of selective serotonin reuptake inhibitors, benzodiazepines, and nonsteroidal anti-inflammatory drugs. We speculated that saishin (Asiasarum root), one of the major components of rikko-san, may reduce peripheral stimulation to the tongue surface through its anesthetic effect. In addition, the transmucosal actions of other components in rikko-san may influence various receptor-related neuropathic pains. In conclusion, rikko-san gargling is efficacious and safe for the treatment of glossodynia.
