Capsaicin is a selective transient receptor potential vanilloid 1 (TRPV1)
ion channel agonist and has been demonstrated to reduce nerve conduction of nociceptive C fibers in the trigeminal nerve without affecting conduction in Adelta fibers. This chapter reviews the classification of chronic
rhinitis subtypes, the prevalence and epidemiology of nonallergic
rhinitis (NAR), postulated pathophysiology and mechanisms of NAR including the role of transient receptor potential (TRP)
ion channels and discusses the potential therapeutic benefits of
capsaicin in the treatment of chronic
rhinitis subtypes, specifically NAR. Evidence supports that
hypersensitivity of TRP
ion channels on sensory afferent neurons innervating nasal mucosa is responsible for inducing NAR symptoms. These symptoms, characterized as excessive nasal glandular secretion, nasal congestion, and
headache, are mediated through
neuropeptide release during axonal and parasympathetic reflexes which are initiated by a spectrum of nonspecific irritants that activate TRP channels. Rational approaches to treat the pathophysiology of NAR would be to develop
therapies with selective TRPV1 agonist activity like
capsaicin that target desensitization of TRP
ion channels on sensory afferent nerves.