title: Epidemiology and differential diagnosis of nasal polyps.
abstract: BACKGROUND
  Chronic rhinosinusitis (CRS) is one of the most common chronic medical conditions, with a significant impact on patient quality of life. CRS is broadly classified into two groups: CRS with nasal polyposis (CRSwNP) and CRS without NP (CRSsNP). Clinically, the major subtypes of CRSwNP may be divided into eosinophilic chronic rhinosinusitis (e.g., allergic fungal rhinosinusitis and aspirin-exacerbated respiratory disease [AERD]) and nasal polyps associated with neutrophilic inflammation (e.g., cystic fibrosis [CF]). CF is characterized by mutation of the gene encoding the CF transmembrane conductance regulator. Functional endoscopic sinus surgery is usually required for most NP patients with increased frequency in patients with AERD. This study provides a review of the epidemiology and major classification of CRSwNP.
  
  
  METHODS
  A review was performed of the literature regarding different subtypes of CRSwNP.
  
  
  RESULTS
  Many definitions of CRSwNP exist and estimates of prevalence vary.
  
  
  CONCLUSIONS
  CRSwNP is a clinical syndrome with a heterogeneous inflammatory profile. Of the subtypes associated with eosinophilic inflammation, AERD remains the most recalcitrant to medical and surgical therapeutic interventions.
authors.affiliation: Department of Surgery, Division of Otolaryngology, the Gregory Fleming James Cystic Fibrosis Research Center, Birmingham, Alabama, USA.
authors.forename: Mohamad R
authors.initials: MR
authors.lastname: Chaaban
authors.forename: Erika M
authors.initials: EM
authors.lastname: Walsh
authors.forename: Bradford A
authors.initials: BA
authors.lastname: Woodworth
mesh_terms: D001241:Aspirin / Q000009:adverse effects; D003550:Cystic Fibrosis / Q000175:diagnosis; D003937:Diagnosis, Differential; D006801:Humans; D009298:Nasal Polyps / Q000175:diagnosis* / Q000453:epidemiology*; D012220:Rhinitis / Q000175:diagnosis; D012852:Sinusitis / Q000175:diagnosis
chemical_list: D001241:Aspirin