Sensitization to aeroallergens and airway hyperresponsiveness at 7 years of age.
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.
Tepas
Elizabeth C
EC
Channing Laboratory, Brigham and Women's Hospital, 181 Longwood Ave, Boston, MA 02115, USA. etepas@partners.org
Litonjua
Augusto A
AA
Celedón
Juan C
JC
Sredl
Diane
D
Gold
Diane R
DR
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
D000485:Allergens; D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride