Chronic rhinosinusitis and neuropeptides.

The nose is an air conditioner and is involved in the protection of the lower airways against inhalation of exogenous particles and airborne irritants. The nasal mucosa is therefore densely innervated by sensory nerves containing several neuropeptides. In the airways, activation of sensory C and A? fibres leads to the release of multiple neuropeptides. In addition to their involvement in vasodilatation, plasma protein exudation and mucus secretion, sensory neuropeptides also participate in inflammatory cell recruitment. This neurogenic inflammation contributes to the intensity of nasal obstruction, rhinorrhea and headaches, the most common symptoms in chronic rhinosinusitis. The concentration of sensory neuropeptides is increased in the nasal mucosa of patients suffering from chronic rhinosinusitis. In contrast, the activity of the enzymes involved in the degradation of these sensory neuropeptides is markedly reduced. These observations should contribute to a better understanding of the pathophysiological mechanisms of one of the most frequently occurring chronic inflammatory diseases.