ATOPIC SENSITIZATION TO FOOD IN INFANCY

Abstract

There is no definitive way to distinguish a true atopic IgE mediated sign or symptom due to a food from an intolerance reaction due to irritation, enzyme deficiency or other idiosyncratic cause. The presence of IgE specific antibody against a food as demonstrated by an immediate weal and flare skin test reaction or a positive RAST is presumptive evidence of a cause and effect relationship. The younger the patient the more likely a positive RAST or skin test is to be significantly causally related to the illness. Never-the-less, in almost 100 infants at four months of age five were observed to have both a positive skin test and a positive RAST to a food, with only two having any detectable allergic illness. This observation in a prospective study of the value of a prophylaxis regimen in the prevention or amelioration of atopic allergic disease in infancy, underlines the problem of the ascertainment of allergy. Under ordinary circumstances an individual with complaints, signs and symptoms of allergic disease consults the physician to help find the cause of the illness. In our double blind prospective study of the value of a prophylaxis regimen in the infants from highly atopic families, evidence of sensitization to food usually precedes the clinical appearance of signs and symptoms of illness. Thus the concordance of disease with positive tests is much lower than is the case in clinical practise.