PURPOSE OF THE STUDY.
To examine whether the timing of introduction of allergenic foods is associated with eczema and wheezing in children ≤4 years of age.
The study included 6905 preschool-aged children participating in the Generation R study, a population-based prospective cohort study in Rotterdam, Netherlands.
Consent for postnatal follow-up was provided by a total of 7893 mothers with a delivery date between April 2002 and January 2006. Timing of introduction of cow’s milk, hen’s egg, peanuts, tree nuts, soy, and gluten was collected by using questionnaires at 6 and 12 months of age. When children were aged 2, 3, and 4 years, information on wheezing and eczema outcomes was obtained via the age-adapted version of the International Study of Asthma and Allergies in Childhood core questionnaire and parental report of physician-diagnosed eczema. Questionnaire response rates were 69%, 64%, and 63% at the ages of 2, 3, and 4 years, respectively.
Of 6905 children, wheezing was reported in 31% at age 2 years and in 14% at ages 3 and 4 years. Eczema was reported in 38%, 20%, and 18% of children at the ages of 2, 3, and 4 years, respectively. The introduction of cow’s milk, hen’s egg, peanuts, tree nuts, soy, and gluten before the age of 6 months was not significantly associated with eczema or wheezing at any age after adjustment for potential confounders, including gender, socioeconomic status of the mother, race/ethnicity, smoking during pregnancy, gestational age at birth, birth weight, parity, breastfeeding, and parental history of atopy. Adjustments were made for additional confounders between ages 12 and 24 months: use of any antibiotics, day care attendance, gastroenteritis, number of respiratory tract infections, and being overweight (P > .10 for all comparisons). The results did not differ after stratifying child’s history of cow’s milk allergy and parental history of atopy.
This study did not demonstrate that the timing of introduction of allergenic foods (cow’s milk, hen’s egg, peanuts, tree nuts, soy, and gluten) was associated with eczema or wheezing in children aged ≤4 years.
Whether timing of introduction of allergenic foods into the infant diet can modify risk of atopic disease in children has not been established. This study is limited by the retrospective nature of parental questionnaires on the timing of allergenic food introduction and reliance on parental report of physician-diagnosed eczema and wheezing. In addition, the authors did not describe the prevalence of solid food introduction before 4 months of age, which, in previous studies, has been shown to be a risk factor for atopic disease. The authors acknowledge the potential for reverse causation as a confounding factor. Nonetheless, this was a large prospective study drawn from the general population, limiting selection bias.
- Copyright © 2012 by the American Academy of Pediatrics