The Spectrum of IgE-Mediated Acute Allergic Reactions to Cow's Milk in Children as Determined by Skin Testing with Cow's Milk Protein Hydrolysate Formulas

Abstract

Children with adverse reactions to cow's milk (CM) often are given infant formulas containing CM proteins (casein or whey proteins) modified by hydrolysis to reduce their allergenicity. Recently, a few reports of acute allergic reactions to these CM hydrolysates have appeared in the medical literature. Therefore, between January 1, 1989, and August 31, 1989, we studied 26 children with a current history of recurrent acute respiratory (asthma, 19/26) or cutaneous (26/26, urticaria) reactions to CM. They were prick skintested with CM, two whey hydrolysates (Good Start HA and Alfaré), and two casein hydrolysates (Nutramigen and Alimentum). Serum-specific IgE (sIgE IU/ml) to CM was measured by the 3M Fast method. Unexpectedly, high frequencies of positive prick tests were found to the whey (69%) and to the casein (38%) hydrolysate products. On the basis of skin test positivity, patients could be separated into three groups: group A (n = 8, positive only to CM), group B (n = 8, positive to CM and whey hydrolysate), and group C (n = 10, positive to CM, whey hydrolysate and casein hydrolysate). This skin test spectrum was reflected by significant differences (A vs B, p < 0.05; A vs C, p < 0.001; B vs C, p < 0.001) between the group means (A = 1.0 ± 0.28; B = 13.4 ± 16.7; C = 33.8 ± 8.8 IU/ml) for sIgE to CM. Asthmatic reactions (100%) and acute generalized urticarial reactions (90%) occurred most frequently in group C patients. When 5 children (A = 2, B = 1, C = 2) were challenged with CM, group C patients had the most severe reactions (urticaria, angioedema, wheezing). Group A patients had milder reactions (contact urticaria). These observations indicate that allergenic determinants for humans are still present in commercially available CM whey and CM casein preparations after hydrolysis. They should be used cautiously. Also, there is a spectrum of immediate reactors (Hill's group I) to CM. We will classify them as IA, IB, and IC in future studies. Perhaps then, the physician caring for children will be able to predict which child with a history of IgE-mediated acute cutaneous and/or respiratory allergic reactions to CM will be able to tolerate "hypoallergenic" CM hydrolysate formulas and which will react adversely to them.