Pathophysiology of allergic rhinitis.

Allergy rhinitis results from an IgE-mediated allergy associated with nasal inflammation of variable intensity. The mechanisms of allergic rhinitis have been clarified using nasal challenge with allergen or proinflammatory mediators and measuring cells and mediators released during the early- and late-phase allergic reaction. However, the priming effect of the nasal mucosa is of importance since a single challenge does not perfectly mimic the ongoing allergic reactions induced by repeated allergen exposure. In seasonal and chronic allergic rhinitis, the same cells and mediators are of importance but nonspecific nasal hyperreactivity develops. The regulation of the inflammation of allergic rhinitis is dependent on adhesion molecules and cytokines.