title: Correlation between nasal symptoms and asthma severity in patients with atopic and nonatopic asthma.
abstract: BACKGROUND
  The association between allergic rhinitis and asthma has been well recognized, and it has been postulated that rhinitis may worsen asthma.
  
  
  OBJECTIVE
  To investigate the severity of asthma among patients with atopic and nonatopic asthma with and without nasal symptoms.
  
  
  METHODS
  Atopic asthmatic patients and nonatopic asthmatic patients were identified from the records of a university-based asthma clinic. A comparison of demographic clinical features was made within and between these 2 asthmatic groups, dichotomized according to the presence or absence of rhinitis.
  
  
  RESULTS
  A total of 178 patients were classified as having atopic asthma and 218 as having nonatopic asthma. The atopic asthmatic patients with nasal symptoms compared with those without had a higher mean forced expiratory volume in 1 second (FEV1), a higher forced vital capacity (FVC), and a higher FEV1/FVC ratio, used fewer oral steroids, and had fewer hospitalizations. The nonatopic asthmatic patients with nasal symptoms compared with those without used more inhaled steroids (and they were also more likely to have nasal polyps on examination). Atopic, relative to nonatopic, asthmatic patients were younger, had a longer duration of asthma, had a higher FEV1/FVC ratio, and took fewer oral steroids.
  
  
  CONCLUSIONS
  Contrary to current hypotheses, in this study the severity of asthma among atopic asthmatic patients was less in those with nasal symptoms. Conversely, among the nonatopic asthmatic patients, asthma was more severe among those with nasal symptoms than those without nasal symptoms.
authors.affiliation: Gage Occupational and Environmental Health Unit, Department of Medicine and Public Health Sciences, University of Toronto, Ontario, Canada.
authors.forename: Amin S
authors.initials: AS
authors.lastname: Kanani
authors.forename: Irvin
authors.initials: I
authors.lastname: Broder
authors.forename: Justina M
authors.initials: JM
authors.lastname: Greene
authors.forename: Susan M
authors.initials: SM
authors.lastname: Tarlo
mesh_terms: D000328:Adult; D000368:Aged; D001249:Asthma / Q000150:complications / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000150:complications; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests; D012221:Rhinitis, Allergic, Perennial / Q000150:complications*; D006255:Rhinitis, Allergic, Seasonal / Q000150:complications*; D012720:Severity of Illness Index