Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is an inflammatory disease of the sinonasal mucosa. It is likely due to a dysregulated immune response directed against, and also modified by, antigens that are present in the paranasal sinuses. The sinonasal microbial flora in CRS patients differs from the sinonasal flora in individuals without CRS. In CRS patients, microbial antigens may be specific targets of the chronic inflammatory response in the paranasal sinuses and may also serve to nonspecifically stimulate the mucosal immune response. Antibiotics do not appear to be beneficial in CRS except possibly to treat some acute exacerbations. This chapter reviews our current understanding of pathophysiology, diagnosis, and treatment of CRS.