Serum specific-IgE antibodies to peptides detected in a casein hydrolysate formula

Up to 2. 59% of infants are affected by cow milk hypersensitivity in the first two years of life, although most of these children will "outgrow" their reactivity within 2-3 years. Extensively hydrolyzed ("hypoallergenic") cow milk-based formulae are often recommended as a substitute formula and are generally well tolerated. However, a small minority of cow milk-allergic children experience allergic reactions to the hypoallergenic formulae as well. Utilizing inhibition-ELISAs and sera from patients with IgE-mediated cow milk allergy, we have identified residual protein fractions less than 20 kD in several of the extensively hydrolyzed cow milk-based formulae. Although many of the cow milk allergic children had positive skin prick lests SPT] to one of the hydrolysate formulae (Nutramigen^ma), the positive skin test result generally did not correlate with clinical reactivity, although the negative predictive value of the negative SPT was excellent. Children with IgE-mediated cow milk allergy and a positive skin prick test to the hypoallergenic formula should probably receive their first dose of the formula in a medical setting so that appropriate therapy can be administered in the unlikely event of an allergic reaction.