[Environment and nasal hyperreactivity].

The nasal mucosa is densely innervated by sensory nerve fibres which play an important part in the protection of the lower airways. Protective reflexes such as sneezing, secretion and nasal congestion can be elicited by exogenous noxious particles and numerous airborne irritants. The functions of the nasal mucosa is influenced at least in part, by biologically active neuropeptides that are released from sensory nerves endings. These sensory neuropeptides are involved in local vasodilatation, vascular permeability and mucus secretion. In addition, these neuropeptides are chemotactic for inflammatory cells such as eosinophiles and granulocytes. Therefore, neuropeptides of sensory origin are most likely involved in the pathophysiological mechanisms of specific (allergy) as well as non specific nasal hyperreactivity.