title: Gender differences in indoor allergen exposure and association with current rhinitis.
abstract: BACKGROUND
  Differences between boys and girls in allergic manifestations are well known, and this difference is possibly not attributed to physiological differences alone.
  
  
  OBJECTIVE
  We, therefore, investigated whether boys and girls could be exposed to different allergen levels at home and whether indoor allergen levels could be differently associated with rhinitis in boys and girls at 10 years of age.
  
  
  METHODS
  Cat, dog and house dust mite (HDM) allergen levels in mattress dust and interview data regarding current allergic disease were available for 797 10-year-old children (360 girls) in The Environment and Childhood Asthma Study in Oslo.
  
  
  RESULTS
  Girls had higher concentrations of cat and dog allergens in their mattresses compared with boys, also in homes without cats [geometric mean 95% confidence intervals (95% CI): 0.37 (0.31, 0.44) for girls and 0.26 (0.23, 0.30) microg cat allergen/g dust for boys, P=0.002], and without dogs [girls: 0.74 (0.63, 0.86) and boys: 0.55 (0.48, 0.62) microg dog allergen/g dust, P=0.003]. No difference was observed for HDM allergen (Der p 1) levels. Of the 190 (23.8%) children reporting current rhinitis, 144 (75.8%) were sensitized to at least one allergen. The adjusted odds ratio for current rhinitis increased with 1.20 (95% CI: 1.01, 1.42) per 1 microg/g dust increase in Der p 1 for girls (P=0.037), but not for boys (P=0.91).
  
  
  CONCLUSIONS
  Girls had higher levels of cat and dog allergens in mattress dust compared with boys, whereas no difference was observed for Der p 1 allergen. Nevertheless, only increasing levels of Der p 1 and not cat and dog allergens significantly increased the risk of current rhinitis in girls, whereas no significant association was observed for boys.
authors.affiliation: Department of Environmental Immunology, Division of Environmental Medicine, Norwegian Institute of Public Health, Nydalen, Oslo, Norway. randi.jacobsen.bertelsen@fhi.no
authors.forename: R J
authors.initials: RJ
authors.lastname: Bertelsen
authors.forename: C
authors.initials: C
authors.lastname: Instanes
authors.forename: B
authors.initials: B
authors.lastname: Granum
authors.forename: K C
authors.initials: KC
authors.lastname: Lødrup Carlsen
authors.forename: G
authors.initials: G
authors.lastname: Hetland
authors.forename: K-H
authors.initials: KH
authors.lastname: Carlsen
authors.forename: P
authors.initials: P
authors.lastname: Mowinckel
authors.forename: M
authors.initials: M
authors.lastname: Løvik
mesh_terms: D016902:Air Pollution, Indoor / Q000009:adverse effects*; D000485:Allergens / Q000009:adverse effects*; D000818:Animals; D039741:Antigens, Dermatophagoides / Q000009:adverse effects; D060829:Arthropod Proteins; D001513:Beds; D002415:Cats; D002648:Child; D003546:Cysteine Endopeptidases; D004285:Dogs; D004391:Dust / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D057805:Pets / Q000276:immunology; D039981:Pyroglyphidae / Q000276:immunology; D012221:Rhinitis, Allergic, Perennial / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors; D012737:Sex Factors
chemical_list: D000485:Allergens; D039741:Antigens, Dermatophagoides; D060829:Arthropod Proteins; D004391:Dust; D003546:Cysteine Endopeptidases; C451162:Dermatophagoides pteronyssinus antigen p 1