Development of atopy and wheezing symptoms in relation to heredity and early pet keeping in a Swedish birth cohort.
The role of pet keeping during infancy for the development of allergy and asthma is still controversial. The objective of this population-based birth cohort study was to assess the development of atopy and different wheezing phenotypes during the first 4 yr of life in relation to heredity and early pet keeping. The cohort comprised all 1228 infants living in a Swedish county who were born over a 1-yr period. The parents replied to repeated questionnaires and 817 of the children were skin prick tested both at 1 and 4 yr. Cat keeping during the first year of life was associated with an increased risk of a positive skin prick test to cat at 1 yr of age [odds ratio (OR) 2.2, 95% confidence interval (CI) 0.9-5.6], but neither with sensitivity nor clinical symptoms of allergy at 4 yr. Dog keeping during the first year of life was associated with an increased risk of early-onset transient wheezing, but only in children with parental asthma (adjusted OR 4.3, 95% CI 1.5-12.1). In contrast, early dog keeping had an inverse association with sensitivity to pollen allergen at 4 yr (adjusted OR 0.3, 95% CI 0.1-0.9) and late-onset wheezing (adjusted OR 0.4, 95% CI 0.2-1.0). Thus, pet keeping during the first year of life was not associated with an increased risk of atopy at 4 yr, although a positive SPT to cat was more common at 1 yr. Our findings may even suggest that dog keeping during the first year of life might provide some protection from pollen allergy and late-onset wheezing and increase the risk of early-onset transient wheezing in children with heredity for asthma.
Department of Paediatrics, Ostersund Hospital, Ostersund, Sweden. annasandin@telia.com
Anna
A
Sandin
Bengt
B
Björkstén
Lennart
L
Bråbäck
D000818:Animals; D001249:Asthma / Q000150:complications / Q000453:epidemiology* / Q000276:immunology; D002415:Cats / Q000276:immunology*; D002675:Child, Preschool; D015331:Cohort Studies; D004285:Dogs / Q000276:immunology*; D018876:Environmental Illness / Q000276:immunology*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology* / Q000276:immunology; D007223:Infant; D007231:Infant, Newborn; D011247:Pregnancy; D015995:Prevalence; D012135:Respiratory Sounds / Q000209:etiology / Q000276:immunology; D012882:Skin Tests; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology