title: The role of atopic sensitization in flexural eczema: findings from the International Study of Asthma and Allergies in Childhood Phase Two.
abstract: BACKGROUND
  The association between allergic sensitization and eczema has been debated for years.
  
  
  OBJECTIVE
  We sought to determine and compare the strength of the association between allergen skin sensitization and eczema in both developing and industrialized countries.
  
  
  METHODS
  Twenty-eight thousand five hundred ninety-one randomly selected 8- to 12-year-old schoolchildren in 20 countries were physically examined for flexural eczema and received skin prick testing to Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat hair, Alternaria tenuis, mixed tree and grass pollen, and allergens of local relevance.
  
  
  RESULTS
  The age- and sex-adjusted odds ratios (ORs) for a positive association between flexural eczema and atopy ranged between 0.74 (95% CI, 0.31-1.81) and 4.53 (95% CI, 1.72-11.93), with a significantly stronger association in affluent compared with nonaffluent countries (combined age- and sex-adjusted OR(affluent) = 2.69 [95% CI, 2.31-3.13] and OR(nonaffluent) = 1.17 [95% CI, 0.81-1.70]). The combined population attributable fraction for atopy in flexural eczema was 27.9% for affluent and 1.2% for nonaffluent-country centers. Correlating gross national per-capita income with either ORs or population attributable fractions for atopy in flexural eczema confirmed a highly significant positive association (P = .006 and P < .001, respectively).
  
  
  CONCLUSIONS
  The association between atopy and flexural eczema is weak and more variable than previously suggested, and the strength of this association is positively linked to gross national income.
authors.affiliation: Centre of Evidence Based Dermatology and the Centre for Population Sciences, Institute of Clinical Research, University of Nottingham, Nottingham, United Kingdom. carsten.flohr@nottingham.ac.uk
authors.forename: Carsten
authors.initials: C
authors.lastname: Flohr
authors.forename: Stephan K
authors.initials: SK
authors.lastname: Weiland
authors.forename: Gudrun
authors.initials: G
authors.lastname: Weinmayr
authors.forename: Bengt
authors.initials: B
authors.lastname: Björkstén
authors.forename: Lennart
authors.initials: L
authors.lastname: Bråbäck
authors.forename: Bert
authors.initials: B
authors.lastname: Brunekreef
authors.forename: Gisela
authors.initials: G
authors.lastname: Büchele
authors.forename: Michael
authors.initials: M
authors.lastname: Clausen
authors.forename: William O C
authors.initials: WO
authors.lastname: Cookson
authors.forename: Erika
authors.initials: E
authors.lastname: von Mutius
authors.forename: David P
authors.initials: DP
authors.lastname: Strachan
authors.forename: Hywel C
authors.initials: HC
authors.lastname: Williams
mesh_terms: D000293:Adolescent; D000485:Allergens / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D000528:Alternaria / Q000276:immunology; D000818:Animals; D039741:Antigens, Dermatophagoides / Q000276:immunology; D002415:Cats / Q000276:immunology; D002648:Child; D019049:Developed Countries; D003906:Developing Countries; D004485:Eczema / Q000453:epidemiology* / Q000276:immunology* / Q000503:physiopathology; D005260:Female; D006197:Hair / Q000276:immunology; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000453:epidemiology* / Q000209:etiology / Q000276:immunology*; D008297:Male; D011058:Pollen / Q000276:immunology; D015995:Prevalence; D012882:Skin Tests; D011795:Surveys and Questionnaires
chemical_list: D000485:Allergens; D039741:Antigens, Dermatophagoides