Endotoxin exposure and eczema in the first year of life

Abstract

Rationale Early life exposure to endotoxin may protect against the development of allergic diseases. Our objective was to examine the relation between endotoxin exposure and eczema in the first year of life in children with parental history of asthma or allergies. Methods Prospective birth cohort study. Results In multivariate analyses adjusting for sex, household income, and season of birth, endotoxin level in the household at age 2 to 3 months 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: P=0.02). Exposure to a dog in the home at age 2–3 months was also inversely associated with eczema in the first year of life, but the confidence interval for the estimate of the association between dog exposure and eczema became wider when endotoxin was included in the multivariate model (OR=0.54, 95% CI=0.27–1.09: P=0.09). 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, P=0.04) and maternal specific IgE positive to =1 allergen (OR=1.61, 95% CI=1.01–2.56, P=0.05). 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 one allergen are associated with an increased risk of eczema in the first year of life.