Clinical symptoms and IgE responses to common food proteins and inhalants in the first 7 years of life.

A group of eighty-six children followed from birth to 4 years of age and previously reported was now re-investigated at the age of 7 years. The prevalence of atopy/allergy was 15%. All of the children with current atopy/allergy had had previous manifestations during their first 4 years of life. No child was allergic to milk at the age of 7 years and only two of the six children with a previous allergy to eggs retained their allergy. No other children had developed allergies to milk or eggs. Only one of the eight children with an elevated level of IgE antibodies to egg white (RAST class 1 or more) during infancy still had increased concentrations of such antibodies. No child had developed an elevated level of IgE antibodies to egg white or milk after the first year of life. Clinical allergies to inhalants had increased from 1% at 4 years of age to 7% at 7 years. Children with elevated levels of IgE antibodies to inhalants had increased from 7% at 4 years of age to 10% at 7 years. The majority of them had had increased levels of IgE antibodies to egg white during infancy. The specificity of an elevated level of cord blood IgE, i.e. above 0.9 kU/l for predicting atopy/allergy during the first 7 years of life and for current atopy/allergy at 7 years of age were both 95%. The corresponding figures for presence of elevated levels of IgE antibodies to egg white (positive RAST) during infancy were 98 and 97%, respectively. The sensitivity of the cord blood IgE predictor was 14 and 17%, respectively and for a positive RAST to egg white during infancy 32 and 50%, respectively.