title: Comparison of orally exhaled nitric oxide in allergic versus nonallergic rhinitis.
abstract: BACKGROUND
  Fractional exhaled nitric oxide (FeNO), a well-known marker of airway inflammation, is rarely evaluated in rhinitis of different etiology. We aimed to compare the eNO levels in allergic rhinitis (AR) and nonallergic rhinitis (NAR) with/without asthma, as well  as the contributing factors that interfere with elevated FeNO.
  
  
  METHODS
  Patients were enrolled based on chronic nasal symptoms. Orally exhaled NO was measured with the single exhalation method at 50 mL/s. All subjects underwent a panel of tests: skin-prick tests, asthma  control test, blood sampling, spirometry, and health-related quality-of-life questionnaires.
  
  
  RESULTS
  The study group consisted of mainly women (130 women/41 men), with a mean age of 32.6 ± 13.2 years. AR was diagnosed in 122 (78.2%), NAR in 34 (21.8%), and 15 subjects  were healthy controls. FeNO was insignificantly higher in patients with AR compared with patients with NAR and controls (32.2 parts per billion [ppb] versus 27 and 19.4 ppb), with no difference between genders. NAR + asthma had higher FeNO than those without asthma (40.5 ppb versus 14.9 ppb;  p < 0.03), whereas accompanying asthma did not affect FeNO levels in the AR group. AR ± asthma had significantly higher FeNO levels than the NAR-only group (p < 0.01). Among AR + asthma, perennial sensitization caused higher FeNO levels than did seasonal allergens (48.5 ±  33.9 and 19.5 ± 13.6' p = 0.003), whereas FeNO was significantly higher during the allergen season. Nasally inhaled corticosteroids insignificantly reduced FeNO levels in all groups. Severity and seasonality of rhinitis, asthma, and ocular symptoms, but not gender, age, body mass  index, Total IgE, forced expiratory volume in 1 second, and smoking, were associated with FeNO.
  
  
  CONCLUSIONS
  Rhinitis and comorbid asthma are responsible for increased FeNO, irrespective of atopy. However, NAR without asthma may not be considered as a strong risk factor  for airway inflammation.
authors.affiliation: Department of Immunology and Allergic Diseases, Faculty of Medicine, Kirikkale University, Kirikkale, Turkey. afusunk@yahoo.com
authors.forename: A Fusun
authors.initials: AF
authors.lastname: Kalpaklioglu
authors.forename: Ilkay K
authors.initials: IK
authors.lastname: Kalkan
mesh_terms: D000328:Adult; D000818:Animals; D001249:Asthma / Q000150:complications / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D001944:Breath Tests; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis*; D012221:Rhinitis, Allergic, Perennial / Q000150:complications / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D006255:Rhinitis, Allergic, Seasonal / Q000150:complications / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D012882:Skin Tests; D013147:Spirometry; D055815:Young Adult
chemical_list: D009569:Nitric Oxide