title: Comparison of deltaFVC between patients with allergic rhinitis with airway hypersensitivity and patients with mild asthma.
abstract: BACKGROUND
  In asthmatic individuals, airway sensitivity and maximal airway response are increased. Airway sensitivity is usually evaluated by measuring the provocation concentration of inhaled methacholine or histamine that causes a decrease in forced expiratory volume in 1 second of 20% (PC20). The percentage decrease in forced vital capacity at the PC20 (deltaFVC) has been proposed as a surrogate marker for maximal airway response. Individuals with allergic rhinitis and no clinical evidence of asthma frequently exhibit airway hypersensitivity.
  
  
  OBJECTIVE
  To compare the deltaFVC between patients with allergic rhinitis and mild asthmatic patients with a similar degree of airway hypersensitivity.
  
  
  METHODS
  A retrospective analysis of methacholine challenge test data from 72 children with allergic rhinitis and airway hypersensitivity (methacholine PC20 < 16 mg/mL) (rhinitis group) and from 72 children with mild atopic asthma matched to the rhinitis group regarding the methacholine PC20 (asthma group). The deltaFVC was calculated on the concentration-response curve to methacholine.
  
  
  RESULTS
  The mean +/- SD deltaFVC was significantly lower in the rhinitis group (15.0% +/- 3.6%) vs the asthma group (17.4% +/- 5.3%) (P = .002). There was no significant correlation between the deltaFVC and PC20 in the rhinitis (r = -0.101; P = .41) and asthma (r = -0.023; P = .85) groups when 2 patients with PC20 less than 1 mg/mL were excluded from each group.
  
  
  CONCLUSIONS
  Patients with allergic rhinitis and airway hypersensitivity had a significantly lower deltaFVC than methacholine PC20-matched mild asthmatic patients, suggesting that the level of maximal airway response in patients with allergic rhinitis is lower than that in mild asthmatic patients with a similar degree of airway hypersensitivity.
authors.affiliation: Department of Pediatrics, Seoul National University Hospital, Seoul, Korea.
authors.forename: Sun Hee
authors.initials: SH
authors.lastname: Choi
authors.forename: Do Kyun
authors.initials: DK
authors.lastname: Kim
authors.forename: Young
authors.initials: Y
authors.lastname: Yoo
authors.forename: Jinho
authors.initials: J
authors.lastname: Yu
authors.forename: Young Yull
authors.initials: YY
authors.lastname: Koh
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000503:physiopathology*; D016535:Bronchial Hyperreactivity / Q000503:physiopathology; D001985:Bronchial Provocation Tests; D016085:Bronchoconstrictor Agents; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D012220:Rhinitis / Q000503:physiopathology*; D014797:Vital Capacity / Q000187:drug effects
chemical_list: D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride