Is breast feeding a risk factor for eczema during the first year of life? Breast feeding (BF) has undisputed advantages over formula feeding, as it provides optimal nutrition, protects against infections, enhances mother–infant bonding, and may improve cog- nitive functions of the offspring (1). Breast feeding may also help prevent childhood over- weight (2). Recently, it was demonstrated that BF provides long-term benefits to the risk of atherosclerosis (3). As Grile´e and Sanford reported a sevenfold increase in the prevalence of eczema in cow’s milk-fed compared with breast-fed children in 1936 (4), BF has also been widely encouraged to reduce the risk of allergic disorders; however, evidence for this effect is conflicting. Some investigators report a protective effect of BF (5–9), whereas others suggest an increased risk for the development of allergy and asthma (10– 13). The reasons for these inconsistent or even contradictory results between studies mainly relate to the use of exclusive vs. partial BF, different cut-off points for BF duration, different duration of follow-up and the ages at which outcomes are assessed. Different confounding factors and inadequate definition of outcomes may also be relevant. Furthermore, methodolo- gical problems, such as selection of study popu- lation and recall bias with respect to feeding history may produce differential bias. Sariachvili M, Droste J, Dom S, Wieringa M, Vellinga A, Hagendorens M, Bridts C, Stevens W, Van Sprundel M, Desager K, Weyler J. Is breast feeding a risk factor for eczema during the first year of life? Pediatr Allergy Immunol 2007: 18: 410–417. Ó 2007 The Authors Journal compilation Ó 2007 Blackwell Munksgaard Breast feeding (BF) provides many advantages to the offspring; how- ever, at present there is an ongoing debate as to whether or not it prevents allergic diseases. The aim of the current study was to investi- gate the effect of duration of BF on eczema in the first year of life. A birth cohort of 1128 infants was followed prospectively from 5 months of pregnancy. Data were collected using questionnaires, a medical examination and blood tests for allergy at the age of 1 yr. Breast feeding was not statistically significant associated with eczema in the first year of life [adj ORs with 95% CIs: 0.8 (0.4–1.3), 0.8 (0.5–1.3) and 1.0 (0.6–1.5) for BF duration of 1–6 wk, 7–12 wk and ‡13 wk, respectively]. Eczema was positively associated with atopy and educa- tional level of the mother, use of antibiotics in pregnancy and passive smoking by the child during the first 12 months. Regular postnatal contact of the infants with dogs was inversely associated with eczema. Breast feeding was positively associated with eczema among children with non-atopic parents [adj ORs with 95% CIs: 2.1 (0.4–10.6), 2.2 (0.4–11.3) and 1.9 (0.4–8.5) for BF duration of 1–6 wk, 7–12 wk and ‡13 wk, respectively], whereas an inverse association was found among children with atopic parents [adj ORs with 95% CIs: 0.6 (0.3–1.3), 0.7 (0.3–1.4) and 0.9 (0.5–1.7) for the same BF durations]. However, these associations were not statistically significant. Breast feeding has no significant effect on the prevalence of eczema in the first year of life. The effect of BF on eczema in children depends on parental atopy. Manana Sariachvili 1 , Jos Droste 1 , Sandra Dom 1 , Marjan Wieringa 2 , Akke Vellinga 1 , Margo Hagendorens 3,4 , Chris Bridts 3 , Wim Stevens 3 , Marc Van Sprundel 1 , Kristine Desager 4 and Joost Weyler 1 1 Department of Epidemiology and Community Medicine, University of Antwerp, Antwerp, Belgium, 2 Department of Otorhinolaryngology, Head and Neck Surgery, Erasmus MC, Rotterdam, the Netherlands, 3 Department of Immunology, University of Antwerp, Antwerp, Belgium, 4 Department of Paediatrics, University of Antwerp, Antwerp, Belgium Key words: breast feeding; eczema; childhood; allergy Manana Sariachvili MD, Department of Epidemiology and Community Medicine, Antwerp University, Universiteitsplein 1, 2610 Wilrijk, Belgium Tel.: 00 323 820 2992 Fax: 00 323 820 2640 E-mail: manana.sariachvili@ua.ac.be Accepted 13 January 2007 Pediatr Allergy Immunol 2007: 18: 410–417 DOI: 10.1111/j.1399-3038.2007.00543.x Ó 2007 The Authors Journal compilation Ó 2007 Blackwell Munksgaard PEDIATRIC ALLERGY AND IMMUNOLOGY 410