It is postulated that this phenomenon is caused by lowered sensory nerve thresholds or antidromic stimulation from neuropeptides that are driving neural hyperresponsiveness.17 Inhibition of the nasal sensory fibers in the afferent limb of these reflexes with small doses of capsaicin causes desensitization and is associated with decreased levels of the transient receptor potential cation channel subfamily V member 1 (TRPV1) and decreased rhinitis symptoms.48,63. This evidence concerns the gene TRPV1 and rhinitis.