Aspirin-Exacerbated Respiratory Disease as an Endotype of Chronic Rhinosinusitis.

Aspirin-Exacerbated Respiratory Disease (AERD) and Chronic Rhinosinusitis with Nasal Polyps (CRSwNP) are both characterized by the presence of chronic sinonasal inflammation and nasal polyps. Unlike in CRSwNP, AERD patients develop respiratory reactions following ingestion of COX-1 inhibitors. AERD patients also, on average, have worse upper respiratory disease with increased sinonasal symptoms, mucosal inflammation and requirements for revision sinus surgery when compared to CRSwNP patients. While no single genetic factor has been identified in either CRSwNP or AERD to date, differences in the metabolism of arachidonic acid as well as innate immune cell activation may uniquely contribute to AERD pathogenesis.