Allergenicity of goat's milk in children with cow's milk allergy

Background: Cow's milk allergy (CMA) is a common disease of infancy and chi ldhood. An appropriate cow's milk (CM) substitute is necessary for feeding babies with CMA. CM substitutes are soy formulas and casein- or whey-based extensively hydrolyzed formulas. In several countries, including Italy, goa t's milk (GM) formulas are available, and some physicians recommend them fo r feeding babies with CMA. Objective: We sought to investigate, in vitro and in vivo, the allergenicit y of GM in 26 children with proven IgE-mediated CMA. Methods: All the children underwent skin tests with CM and GM; detection of specific serum IgE to CM and GM; and double-blind, placebo-controlled, ora l food challenges (DBP-COFCs) with fresh CM, GM, and, as placebo, a soy for mula (Isomil, Abbott, Italy), CAP inhibition and immunoblotting inhibition assays were also carried out in 1 of 26 and 4 of 26 children with positive RAST results to both CM and GM, respectively. Results: All the children had positive skin test responses and CAP results to both CM and GM, all had positive DBPCOFC results to CM, and 24 of 26 had positive DBPCOFCs to GM. In CAP inhibition tests, preincubation of serum w ith CM or GM strongly inhibited IgE either to CM or to GM, In immunoblottin g inhibition assays, preincubation with CM completely extinguished reactivi ty to GM, whereas GM partially inhibited reactivity to CM. Conclusions: These data strongly indicate that GM is not an appropriate CM substitute for children with IgE-mediated CMA. A warning on the lack of saf ety of GM for children with CMA should be on the label of GM formulas to pr event severe allergic reactions in babies with CMA.