title: Controversial role of pets in the development of atopy in children.
abstract: BACKGROUND
  Exposure to environmental allergens originating from different sources has been implicated in the sensitization to the respective allergens and development of atopic diseases. Keeping domestic animals is associated with exposure to relevant allergens but there are controversial data whether this exposure promotes or protects from the development of atopy.
  
  
  METHODS
  We herein reviewed the literature regarding the available data for the exposure to pets (cats and/or dogs) and the development of atopy. For this purpose, we searched the PubMed database.
  
  
  RESULTS
  This review attempts to answer the following questions that arise from the daily practice and the relevant studies, which are: a) is pet keeping associated with sensitization? b) is there an association between keeping pets and the development of asthma, allergic rhinitis and eczema, and, c) what is the underlying mechanism of any possible protective association? Despite the fact that several studies and meta-analyses have been conducted to explore the role of pets in the development of atopy, there are still conflicting pieces of evidence. It seems that there are different effects depending on the type of pets, the time and duration of exposure, and the genetic background of the individual.
  
  
  CONCLUSIONS
  Further appropriately designed birth cohort studies are needed to explore whether exposure to relevant allergens from pets promotes or protects from the development of atopy.
authors.affiliation: Third Department of Pediatrics, Attikon University Hospital, School of Medicine, University of Athens, Athens, Greece. mar.moustaki@gmail.com
authors.forename: Andrew
authors.initials: A
authors.lastname: Fretzayas
authors.forename: Doxa
authors.initials: D
authors.lastname: Kotzia
authors.forename: Maria
authors.initials: M
authors.lastname: Moustaki
mesh_terms: D000818:Animals; D001249:Asthma / Q000276:immunology; D002415:Cats; D002648:Child; D004285:Dogs; D004485:Eczema / Q000276:immunology; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology*; D057805:Pets; D065631:Rhinitis, Allergic; D012221:Rhinitis, Allergic, Perennial / Q000276:immunology