(HealthDay News) — Exposure to secondhand tobacco smoke (SHS) in infancy is associated with increased risk of sensitization to food allergens up to age 16 years, according to a study published online October 16 in Allergy.

Jesse D. Thacher, MPH, from Karolinska Institutet in Stockholm, and colleagues examined whether maternal smoking during pregnancy and postnatal SHS exposure contribute to allergic sensitization in children up to age 16 years. Data were included for 3,316 children from a birth cohort who were followed for 16 years. Repeated parental questionnaires were used to assess SHS exposure and symptoms of allergic disease.

The researchers found that exposure to SHS in infancy without exposure in utero correlated with an increased risk of food sensitization at age 4 (odds ratio, 1.47; 95% confidence interval, 1.08–2.00); comparable odds ratios were seen at ages 8–16 years. There was an overall correlation between SHS in infancy and food sensitization up to age 16 years in longitudinal analyses (odds ratio, 1.24; 95% confidence interval, 0.98–1.56). There was no correlation seen for maternal smoking during pregnancy with sensitization up to age 16 years. SHS in infancy correlated with overall increased risk of eczema with sensitization when sensitization was combined with concurrent symptoms of allergic disease (odds ratio, 1.62; 95% confidence interval, 1.20–2.18).

“SHS exposure in infancy appears to increase the risk of sensitization to food allergens up to age 16 years as well as eczema in combination with sensitization,” the authors write.

Full Text