Breast-feeding and the onset of atopic dermatitis in childhood: A systematic review and meta-analysis of prospective studies

Background: Despite the numerous studies on the possible protective effect of breast-feeding against the onset of atopic dermatitis during childhood, this issue remains controversial. Objective: We conducted a systematic review with meta-analysis of prospective studies that evaluated the association between exclusive breast-feeding during the first 3 months after birth and atopic dermatitis. Methods: A comprehensive search of the 1966-2000 MEDLINE database and review of the reference lists of relevant articles identified 18 prospective studies that met the predefined inclusion criteria. By means of a standardized approach, 2 of the investigators independently assessed the methodologic quality of the studies, duration and exclusivity of breast-feeding, outcome measures, and control for potential confounding factors. The same approach was applied during data abstraction and evaluation of the estimates of association. Summary measures of association were then calculated. Results: The summary odds ratio (OR) for the protective effect of breast-feeding in the studies analyzed was 0.68 (95% confidence interval [CI], 0.52-0.88). This effect estimate was higher in the group of studies wherein children with a family history of atopy were investigated separately (OR=0.58; CI, 0.41-0.92) than in those of combined populations (OR=0.84; CI, 0.59-1.19). A small subset of studies of children without a history of atopy in first-degree relatives showed no association between breast-feeding and the onset of atopic dermatitis (OR=1.43; CI, 0.72-2.86). Conclusion: Exclusive breast-feeding during the first 3 months of life is associated with lower incidence rates of atopic dermatitis during childhood in children with a family history of atopy. This effect is lessened in the general population and negligible in children without first-order atopic relatives. Breast-feeding should be strongly recommended to mothers of infants with a family history of atopy, as a possible means of preventing atopic eczema.