Predisposing factors and the development of reaginic allergy in infancy.

In a prospective study of fifty-eight newborn infants of parents with reaginic allergy, twenty-seven developed eczema and twenty-eight positive prick tests to one or more of six antigens during the first year of life. These reaginic manifestations were related to presymptomatic transient IgA deficiency. The development of positive skin tests was also related to HLA A1 B8, and to season of birth. The order of frequency of positivity was Dermatophagoides, grass pollens, cat fur, feathers and cow's milk. The skin tests were often positive in infants in whom serum IgE was not detected. The eczema disappeared and the skin tests became negative in some infants at the end of the first year. This work suggests that sensitization in the new-born period is important in the subsequent development of disease.