Effect of breast-feeding on the development of atopic dermatitis.

Atopy can be defined as the genetically determined risk to develop allergic disease. Avoidance of one specific allergen may decrease the risk for sensitization against this allergen, but it will not affect atopy. Our aim was to investigate if exclusive breast-feeding is associated with atopic dermatitis during the first 5 years of life. Data on 200 children were taken from parental-administered questionnaires from a case control study in Birjand - Iran (recruited 2003) comprised of a case (100 children with atopic dermatitis) and a control (100 normal children) subgroup. Outcomes were physician-diagnosed atopic dermatitis (AD) and itchy rash. Data were analyzed by using SPSS package, Chi square and Exact Fisher tests.Thirty-four of the case and 50 of control group were exclusively breast-fed, whereas 6 of the case and 2 of control group were exclusively cow milk-fed. These differences were statistically significant. (P less than 0.05). Duration of breast-feeding in case and control group was different. These differences were statistically significant (P less than 0.001). Duration of cow's milk formula feeding in case and control group was different, but these differences were not statistically significant. (P=0.6) Positive family history of allergy in case and control group was 63% and 23% respectively and this difference was statistically significant (P less than 0.001). These findings support the hypothesis that exclusive breast-feeding is a protective factor for development of atopic dermatitis if compared with conventional cow's milk formula.