The development of allergy in high-risk children

BACKGROUND: It is uncertain as to what extent the development of allergic disease in childhood is predictable during early infancy. A number of environmental factors have been suspected of increasing the risk of acquiring allergy, but the evidence is conflicting. OBJECTIVE: To observe the development of atopy and allergic disease in a cohort of high-risk children so as to determine the importance of certain environmental factors and to study the relationship between early and later manifestations. METHODS: A cohort of infants, all at high risk of allergy, was followed up from birth to the age of 7 years. In half, selected at random, cow's milk protein was avoided for 4 months. Skin-prick tests were performed and serum IgE measured in infancy and at 7 years, when an AlaTOP test was also performed. RESULTS: Skin sensitivity to egg in the first year of life was strongly associated with eczema, asthma, mite sensitivity and serum IgE at the age of 7 years, when mother's atopic history was associated with AlaTOP status, father's atopic history with skin sensitivity, and male sex with both. Maternal smoking during pregnancy was associated positively with IgE at 3 months and negatively with skin sensitivity at 7 years. The development of allergy was unrelated to infant feeding method or number of older siblings. CONCLUSION: Allergic disease in childhood is to a large degree determined before birth or during infancy.