The role of allergic rhinitis in upper respiratory tract inflammatory diseases

Summary The number of patients with allergic rhinitis (AR) is increasing. Furthermore, patients with otitis media with effusion (OME) and chronic sinusitis (CS) are frequently complicated with AR. These findings suggest that AR has an impact on the pathogenesis of both OME and CS. The direct and indirect influence of AR on OME and CS was investigated by clinical and experimental studies to clarify the mechanism by which type I allergic reaction is associated with OME and CS. Clinical findings of patients with OME or CS complicated with AR were analysed and compared with those of nonallergic subjects. Samples such as sinus effusions and middle ear effusions (MEE) were collected from the patients and infiltration of inflammatory cells and concentrations of inflammatory cytokines determined. In addition, previous reports discussing the relationship between AR and OME or CS are reviewed. Eosinophil infiltration and oedema were remarkable in paranasal sinus mucosa of patients with CS complicated with AR, suggesting the presence of type I allergic reaction in sinus mucosa. However, there was little evidence of eosinophils in sinus effusions. Endotoxin was frequently detected in sinus effusions of patients with CS having AR as well as suppurative CS. Hypoxia was also considered an important factor inducing sinus pathology. Eosinophils and IgE antibodies in MEE were not increased in OME patients with AR. Anti-allergic medicine was effective in OME patients complicated with AR and improvement of nasal symptoms significantly correlated with that of ear symptoms. AR might be directly and indirectly associated with the pathogenesis of OME and CS.