Early risk factors for cow's milk allergy in children in the first year of life.

Abstract

Background: Cow's milk allergy (CMA) is a key form of food allergy (FA). It was shown that the frequency of FA seems to have increased during the past 10-20 years, which led to the thought that FA may have different risk factors. Epigenetic regulations and environmental pre- and postnatal factors play a large role in contributing to allergy. Understanding the risk factors that pertain to the development of FA may help to provide reasonable recommendations for prevention of the disease. Objective: To assess the impact of perinatal and environmental risk factors on the incidence of CMA in children in the first year of life. Methods: The study group consisted of 138 infants with CMA and 101 healthy infants without allergy. CMA was confirmed by an elimination test and oral food challenge. To assess infant, parental, and environmental risk factors, we used a validated questionnaire survey. Results: The incidence of CMA was three times higher in infants with a positive family history for allergy (p < 0.001). An analysis revealed that mothers of children with CMA were fourfold more frequently university educated than mothers of children without allergy (p < 0.0001). The ages of the mothers from the study group were significantly higher than the ages of the mothers from the control group. Children from the study group were breast-fed for a significantly shorter time than children from the control group. The risk of CMA was threefold lower in children who had pets at home (p = 0.0002). The risk of IgE-mediated CMA was twofold higher than the risk of non-IgE-mediated CMA if the family had more children (p = 0.04) and as many as ninefold higher if multiorgan symptoms were detected (p = 0.01). Conclusion: A positive family history of allergy and mother's education increased the risk of CMA in children in the first year of life, whereas having pets at home and a longer period of breast-feeding decreased the risk.