title: Sensitization to aeroallergens and airway hyperresponsiveness at 7 years of age.
abstract: OBJECTIVE
  To investigate the relationship between current and early life factors and airway responsiveness to inhaled methacholine in children with a median age of 7.0 years.
  
  
  METHODS
  Study subjects were a subset of a prospective birth cohort of children in the Boston area at high risk for atopy.
  
  
  METHODS
  One hundred thirty-one children underwent both skin-prick testing to a panel of aeroallergens and a methacholine challenge test between 6.5 years and 8.8 years of age. Telephone questionnaires were performed at set intervals, and home dust samples were collected in the first year of life.
  
  
  RESULTS
  Of the 131 participating children, 51% (67 patients) had at least one positive skin-prick test response and 28% (37 patients) had airway hyperresponsiveness (AHR) [provocative concentration of methacholine causing a 20% fall in FEV(1) of < 4 mg/mL]. After adjusting for relevant covariates, AHR was strongly associated with sensitization to at least four aeroallergens (odds ratio [OR], 13.41; 95% confidence interval [CI], 3.03 to 59.42). In separate adjusted models, sensitization to cat (OR, 14.73; 95% CI, 3.64 to 59.55), dust mite (OR, 5.13; 95% CI, 1.94 to 13.56), cockroach (OR, 4.00; 95% CI, 1.19 to 13.50), and ragweed (OR, 10.08; 95% CI, 2.31 to 44.10) were significant predictors of AHR. However, no relationship was found with early life exposure to perennial aeroallergens or other perinatal and first-year-of-life factors.
  
  
  CONCLUSIONS
  Among young children at risk for atopy, sensitization to specific aeroallergens, but not early life exposures, is associated with increased airway responsiveness.
authors.affiliation: Channing Laboratory, Brigham and Women's Hospital, 181 Longwood Ave, Boston, MA 02115, USA. etepas@partners.org
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Tepas
authors.forename: Augusto A
authors.initials: AA
authors.lastname: Litonjua
authors.forename: Juan C
authors.initials: JC
authors.lastname: Celedón
authors.forename: Diane
authors.initials: D
authors.lastname: Sredl
authors.forename: Diane R
authors.initials: DR
authors.lastname: Gold
mesh_terms: D000485:Allergens; D001249:Asthma / Q000209:etiology*; D016535:Bronchial Hyperreactivity / Q000453:epidemiology*; D001985:Bronchial Provocation Tests; D016085:Bronchoconstrictor Agents; D002648:Child; D015331:Cohort Studies; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000453:epidemiology*; D019570:Inhalation Exposure; D016210:Methacholine Chloride; D018570:Risk Assessment; D012882:Skin Tests
chemical_list: D000485:Allergens; D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride