title: Pet-keeping in early childhood and airway, nose and skin symptoms later in life.
abstract: BACKGROUND
  It is discussed whether exposure to pets during childhood is a risk or a protective factor for sensitization and allergic symptoms. The aim of this study was to investigate the association between pet-keeping at time of birth and allergic symptoms in airways, nose and skin among young children in Sweden.
  
  
  METHODS
  A questionnaire was sent to the parents of 14 077 children (1-6 years), the focus being on allergic symptoms, home environment and other background factors including pet-keeping and avoidance behaviour. The response rate was 79%.
  
  
  RESULTS
  Almost one-tenth of the population had got rid of pets because of allergy in the family, and 27.3% reported "avoidance" behaviour towards pets. In a cross-sectional analysis current pet-keeping was "protective", but this may be due to the fact that people avoid exposing their child to something that they believe is a risk factor for allergies. Pet-keeping at the time of birth was associated with "wheezing", "asthma" and "rhinitis on pet-exposure" later in life for children from families with an "avoidance" behaviour, and was not "protective" for other children. There was also an indication of a dose-response relationship between the number of types of furred pets at time of birth and later symptoms in analyses adjusted for avoidance behaviour or current pet-keeping.
  
  
  CONCLUSIONS
  The distribution of pet-keeping in the population is largely explained by avoidance behaviour, meaning that those who have pets mainly are those who can stand them, indicating a "healthy pet-keeping effect".
authors.affiliation: Swedish National Testing and Research Institute, Boras, Sweden.
authors.forename: C G
authors.initials: CG
authors.lastname: Bornehag
authors.forename: J
authors.initials: J
authors.lastname: Sundell
authors.forename: L
authors.initials: L
authors.lastname: Hagerhed
authors.forename: S
authors.initials: S
authors.lastname: Janson
mesh_terms: D000818:Animals; D000829:Animals, Domestic / Q000276:immunology*; D001362:Avoidance Learning; D002648:Child; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000209:etiology; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology / Q000209:etiology* / Q000523:psychology; D007223:Infant; D007231:Infant, Newborn; D015995:Prevalence; D012130:Respiratory Hypersensitivity / Q000209:etiology; D012220:Rhinitis / Q000209:etiology; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology