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.