Exposure to household endotoxin and total and allergen-specific IgE in the US population

Although endotoxin has strong pro-inflammatory properties, endotoxin-allergy relationship in adults and children have been inconsistent.

We investigated the association between household endotoxin levels and total immunoglobulin E (IgE) or specific IgE in the US general population, classified into three age ranges: children/adolescent, adults, and older adults.

We analyzed the 2005-2006 National Health and Nutrition Examination Surveys. A total of 5220 participants for whom serum IgE and household endotoxin data were available was included in the analyses.

Exposure to endotoxin reduced the risk for allergic sensitization, especially in specific IgE to plants (OR in Quartile 3 = 0.58; 95% CI = 0.44-0.76) and pets (OR in Quartile 3 = 0.62; 95% CI = 0.41-0.92), for children/adolescents. In contrast, the risk among adults and older adults increased with increasing endotoxin levels.

Our findings suggest that the effect of endotoxin on allergic reaction is likely to depend on age.