title: Endotoxin exposure and eczema in the first year of life.
abstract: OBJECTIVE
  Exposure to endotoxin in early life has been proposed as a factor that may protect against the development of allergic diseases such as eczema. The objective of this study was to examine the relation between endotoxin exposure in early life and eczema in the first year of life in children with parental history of asthma or allergies.
  
  
  METHODS
  This study used a prospective birth cohort study of 498 children who had a history of allergy or asthma in at least 1 parent and lived in metropolitan Boston. A subset of 401 living rooms had house dust samples adequate for analysis of endotoxin.
  
  
  RESULTS
  In multivariate analyses adjusting for gender, income, and season of birth, endotoxin levels in the living room at 2 to 3 months of age was inversely associated with physician- or nurse-diagnosed eczema in the first year of life (odds ratio [OR] for each quartile increment: 0.76; 95% confidence interval [CI]: 0.61-0.96). Exposure to a dog in the home at age 2 to 3 months was also inversely associated with eczema in the first year of life, but the CI widened when endotoxin was included in the multivariate model (OR: 0.54; 95% CI: 0.27-1.09). Other variables associated with eczema in the first year of life included paternal history of eczema (OR: 1.91; 95% CI: 1.03-3.55) and maternal specific immunoglobulin E positivity to > or =1 allergen (OR: 1.61; 95% CI: 1.01-2.56).
  
  
  CONCLUSIONS
  Among children with parental history of asthma or allergies, exposure to high levels of endotoxin in early life may be protective against eczema in the first year of life. In these children, paternal history of eczema and maternal sensitization to at least 1 allergen are associated with an increased risk of eczema in the first year of life.
authors.affiliation: Department of Pediatrics, Division of Allergy and Immunology, Children's Hospital, Boston, Massachusetts 02115, USA. wanda.phipatanakul@childrens.harvard.edu
authors.forename: Wanda
authors.initials: W
authors.lastname: Phipatanakul
authors.forename: Juan C
authors.initials: JC
authors.lastname: Celedón
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Raby
authors.forename: Augusto A
authors.initials: AA
authors.lastname: Litonjua
authors.forename: Donald K
authors.initials: DK
authors.lastname: Milton
authors.forename: Diane
authors.initials: D
authors.lastname: Sredl
authors.forename: Scott T
authors.initials: ST
authors.lastname: Weiss
authors.forename: Diane R
authors.initials: DR
authors.lastname: Gold
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001249:Asthma; D015331:Cohort Studies; D004285:Dogs / Q000276:immunology; D004391:Dust / Q000276:immunology*; D004485:Eczema / Q000517:prevention & control*; D004731:Endotoxins / Q000032:analysis*; D004781:Environmental Exposure / Q000032:analysis*; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007223:Infant; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D012307:Risk Factors
chemical_list: D004391:Dust; D004731:Endotoxins; D007073:Immunoglobulin E