Nonallergic rhinitis

Asthma

Biology

Genus

Endoscopic sinus surgery

Surgery

Chronic rhinosinusitis

Sinusitis

Sinus (botany)

Botany

Immunology

Nasal polyps

Eosinophil

Mucosal inflammation

Functional endoscopic sinus surgery

Pathophysiology

Inflammation

Allergy

Medicine

Eosinophilia

Pathology

Allergy Asthma and Immunology Research

Chronic rhinosinusitis (CRS) with or without nasal polyposis is a complex medical condition characterized by varying patterns of chronic innate and adaptive mucosal inflammation. Treatment of CRS has been traditionally limited to corticosteroids and sinus surgery; however, novel biologics have more recently been evaluated as steroid- and surgery-sparing options. While it is clear that there are different subtypes or endotypes of CRS, perhaps the most frequent presentation involves the features of type 2 inflammation, including a prominent tissue eosinophilia component. The purpose of this review is to provide an update on eosinophil biology as well as on the potential contribution of eosinophils and their mediators to the pathophysiology of CRS, drawing mechanistic conclusions mainly from studies of human sinus mucosal tissues, nasal secretions, and benefits (or lack thereof) from the use of various pharmacotherapies. The unavoidable conclusion derived from this approach is that eosinophils themselves cannot fully explain the underlying pathophysiology of this complex disorder.

Biology and Function of Eosinophils in Chronic Rhinosinusitis With or Without Nasal Polyps