Diagnosis and Classification of Chronic Rhinosinusitis with and Without Polyposis in Adults and Children

Abstract

Chronic rhinosinusitis (CRS) is defined as a group of disorders characterized by inflammation of the mucosa of the nose and paranasal sinuses of at least 12 consecutive weeks’ duration. CRS has been subclassified in both children and adults as “CRS without nasal polyps” (CRSsNP), “CRS with nasal polyps” (CRSwNP), and “allergic fungal rhinosinusitis” (AFRS). This chapter discusses the evolution of the term “rhinosinusitis,” compares and contrasts the features of CRS in children and adults, and discusses the cardinal symptoms of CRS by subtype and their sensitivity and specificity for diagnosis and the importance of objective measures (radiographic or endoscopic) in establishing the diagnosis. The pathophysiology and clinical presentation of each CRS subtype is discussed. Clinical and pathophysiologic differences between CRSsNP and CRSwNP and their impact on medical or surgical treatment are discussed. The chapter concludes with a discussion of potential future refinements in CRS classification, taking into account such factors as the nature of microbial colonization, defects in local innate immunity, and local adaptive Th2 “allergic” (“eosinophilic”) responses to microbes that impact significantly on expression of the disease. For example, the presence of bacterial biofilm on sinonasal mucosal surfaces is associated with more severe preoperative disease and persistent mucosal inflammation following endoscopic sinus surgery. Further dissection of the host-microbial interactions in CRS is likely to converge in some areas (e.g., uncovering defects in local innate immunity predisposing to bacterial biofilm formation) but diverge in others forcing us to reconsider our current paradigms, such as the distinction between CRSsNP and CRSwNP.