Chronic Rhinosinusitis (CRS)

Chronic rhinosinusitis (CRS) represents an inflammatory process of the sinonasal mucosa that persists for a period of at least 12 weeks. There are several triggers, modifiers, and common inflammatory mediators that contribute to the pathogenesis of CRS. CRS phenotypes are based upon differences in physical characteristics of disease expression and are considered as a preliminary step toward a directed treatment strategy. The two major phenotypes are CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). The association between nasal polyps and allergic rhinitis is complex. The phenotypes are linked to the endotypes of CRS whic are determined by the predominant inflammatory markers. The diagnosis of CRS requires the presence of at least two or more recognized symptoms, as well as evidence of inflammation as demonstrated by endoscopic or radiologic examination. The clinical picture and management of CRSsNP are distinct from CRSwNP. Treatment-resistant CRSsNP might point to an underlying cause (secondary CRS) which warrants further workup.