Environmental and Dietary Risk Factors for Infantile Atopic Eczema Among a Slovak Birth Cohort
Authors: Skripak Justin , Wood Robert A. 
Published: November 2007

Dunlop A, Reichrtova E, Palcovicova L, et al. Pediatr Allergy Immunol. 2006;17:103–111

PURPOSE OF THE STUDY. To evaluate and quantify how various modifiable environmental and dietary exposures contribute to the development of infantile atopic eczema (AE).

STUDY POPULATION. Birth cohort of 1990 infants followed and evaluated at 12 months of age.

METHODS. Parents completed 2 questionnaires: 1 during the mother's admission for delivery and 1 at the 12-month follow-up appointment. At the follow-up visit, children were examined by an allergist who performed an assessment of AE on the basis of the scoring atopic dermatitis (SCORAD) index. Data analysis (univariate and multivariate) was performed to evaluate the effects of “modifiable” and “nonmodifiable” exposures on development of AE.

RESULTS. At the 12-month follow-up, 1326 (67%) of the children remained in the cohort, of which 207 (15.6%) were determined to have AE. There were several modifiable factors found to be significant in univariate and/or multivariate analysis. Ownership of livestock and exclusive breastfeeding for at least 4 months were protective. Exposure to any infant formula (cow's milk formula specifically), eggs, or fish in the first year of life, parental smoking, and cat ownership were associated with increased AE. There were also several significant nonmodifiable exposures. Residing in an agricultural region and birth in the spring as compared with the winter were protective. Maternal or paternal history of atopy, high paternal education, and residence in a rural region or in a “town” as compared with a “village” were associated with increased AE. The impact of modifiable versus nonmodifiable exposures on outcome was evaluated by calculating a percent total regression score. Using this method, modifiable exposures were found to contribute just over one third (38%) to the total regression score, whereas nonmodifiable exposures contributed just under two thirds (62%).

CONCLUSIONS. Although nonmodifiable exposures seem to have greater overall impact on development of AE, modifiable exposures seem to contribute significantly as well. Among these, infant feeding practices (including breastfeeding and exposure to cow's milk, egg, and fish) in the first year of life are the biggest factors.

REVIEWER COMMENTS. The finding that breastfeeding is protective against developing AE is consistent with multiple previous studies, although there are also quite a few studies that have found no effect. This effect is seen primarily in children with a family history of atopy. There are also other data that support the concept of early sensitization to certain foods, including cow's milk, eggs, and fish, increasing the risk for AE. Cat ownership has frequently been noted to be a risk factor, whereas living environments that result in exposure to livestock have been protective. This study adds to the data suggesting that among infants at high risk of developing AE, there are some exposure factors that may be modified to lessen the likelihood of developing AE. Because infantile AE is associated with the development of asthma later, one may presume that preventing AE could decrease the odds of developing asthma as well.