Advances in Chronic Rhinosinusitis: Pathobiology, Endotyping, and Biologic Therapy

This chapter reviews the evolving understanding of the pathobiological mechanisms underlying chronic rhinosinusitis, with particular emphasis on type 2 and non-type 2 inflammatory endotypes, the role of the sinonasal microbiome, and epithelial barrier dysfunction. It critically evaluates the expanding role of biologic agents — including anti-IL-4/13, anti-IL-5, and anti-IgE therapies — alongside advances in functional endoscopic sinus surgery and evidence-based long-term management strategies.