TABLE 1.

Suggested subclassification schemas for subtypes of CRS^a

Subtype(s)	Definition	Distinguishing characteristic(s)	Clinical finding(s)	Reference(s)
CRSsNP	Chronic rhinosinusitis without nasal polyps	Polyposis	Tends to be Th1-skewed neutrophilic disease with fibrosis and often high levels of collagen deposition, basement membrane thickening, and goblet cell hyperplasia	2, 45–47
CRSwNP	Chronic rhinosinusitis with nasal polyps	Polyposis	Tends to be eosinophilic disease associated with edema and elevated inflammatory signaling; generally Th2-skewed immune response in Caucasian populations but Th1 in Chinese populations and Th17 in cystic fibrosis patients; presence of polyposis in patients tends to be associated with worse preoperative CT and both pre- and postoperative symptom scores	2, 4, 7, 45–51
eCRSsNP	Eosinophilic chronic rhinosinusitis without nasal polyps	Polyposis, eosinophilia	Appears to be uncommon
neCRSsNP	Noneosinophilic chronic rhinosinusitis without nasal polyps	Polyposis, eosinophilia	Tends to be representative of most CRSsNP patients	46, 51
eCRSwNP	Eosinophilic chronic rhinosinusitis with nasal polyps	Polyposis, eosinophilia	Tends to be representative of most cases of CRSwNP in Caucasian populations; eosinophilia correlates with both frequency of polyps and comorbid asthma and tends to be associated with worse preoperative CT and both pre- and postoperative symptom scores than neCRSwNP	2, 4, 7, 45–51
neCRSwNP	Noneosinophilic chronic rhinosinusitis with nasal polyps	Polyposis, eosinophilia	Tends to be the most common form of CRSwNP in Chinese populations (Th1) and cystic fibrosis patients (Th17)	2, 4, 7, 45, 47–51
CHES, ECHRS	Chronic hyperplastic eosinophilic sinusitis, eosinophilic chronic hyperplastic rhinosinusitis	Hyperplasia	Comparable to eCRSwNP	49, 52
CIS, NECHRS	Chronic inflammatory sinusitis, noneosinophilic chronic hyperplastic rhinosinusitis	Hyperplasia	Comparable to neCRSwNP	49, 52
eCRSsNP, neCRSsNP, eCRSwNP, neCRSwNP, CHES, ECHRS, CIS, and NECHRS with or without polyposis, eosinophilia, neutrophilia, asthma, atopy, allergic fungal rhinosinusitis, aspirin-exacerbated respiratory disease, cystic fibrosis		Polyposis, eosinophilia, neutrophilia, asthma, atopy, allergic fungal rhinosinusitis, aspirin-exacerbated respiratory disease, cystic fibrosis	Asthmatic, aspirin-exacerbated respiratory disease, and allergic fungal rhinosinusitis patients tend to have higher CT and endoscopy scores and higher rates of polyposis and eosinophilia; nonasthmatic patients, in contrast, tend to have disease more associated with purulence but with lower CT scores than those of their asthmatic counterparts; cystic fibrosis patients represent a mix of the above-described patterns, associated with both purulence and higher CT scores	53
CRS, delineated into 10 distinct subclusters of underlying inflammatory profiles		Distinct profiles of tissue inflammatory markers		44

^aCT, computed tomography.