Background: Several authors described capsaicin, the pungent substance in red pepper, as an efficacious therapy for non-allergic non-infectious perennial rhinitis (NANIPER). Repeated capsaicin application induces peptide depletion and specific degeneration of the unmyelinated sensory C-fibres in the nasal mucosa.
Methods: We performed a placebo-controlled (NaCl 0.9%) study with 25 NANIPER patients. Daily record charts and visual analogue scales (VAS) were used for clinical evaluation. Nasal lavages were obtained before, during, and after treatment.
Results: There was a significant and long-term reduction in the VAS scores in the capsaicin group. No significant difference was found between the placebo and capsaicin treated groups for the mean group concentrations of leukotriene (LT) C4/D4/E4, prostaglandin D2 (PGD2), and tryptase. The levels of mast cell mediators, tryptase and PGD2, and leukotrienes, mediators derived from a variety of inflammatory cells, were low at baseline and comparable with levels observed in nasal lavages obtained from normals.
Conclusion: As involvement of inflammation could not be demonstrated, it is not surprising that capsaicin has no effect on inflammatory mediators. This suggests that inflammatory cells do not play a major part in the pathogenesis of NANIPER.