Neuro-immunological Analysis of Idiopathic Rhinitis Patients and Controls Treated With Capsaicin.

The term idiopathic rhinitis (IR) is used in this study to describe a patient group with following characteristics: patients with complaints of nasal obstruction, sneezing and/or rhinorrhea for a period of over 1 year, which cannot be attributed to allergy, nasal or paranasal infection, anatomical disorders, pregnancy or lactation and/or systemic disorders. These patients are non-smokers and do not use medication affecting nasal function. They have no beneficial effect of intranasal steroid spray (INS) treatment. The population incidence of IR is estimated to be as high as 10%. The pathophysiology of IR is largely unknown. Several hypotheses have been put forward. In general it is assumed that neurogenic mechanisms play an important role. Neuropeptides like CGRP, SP, NKA/B, NPY, NGF are released from afferent neurons in the nasal mucosa after activation by unspecific stimuli and can be responsible for the symptoms of IR. For this group of IR-patients, there is until now only one treatment option: intranasal capsaicin application. Capsaicin, the pungent agent in hot pepper, is supposed to exert its' therapeutic effect via degeneration or desensitization effect on the afferent C-fibers. The hypothesis is that nasal capsaicin treatment reduces neurogenic inflammation and reduces in that way nasal symptoms.