Eating baked cow’s milk products may facilitate resolution of cow’s milk allergy

Kim et al. (J Allergy Clin Immunol 2011;128:125-131.e2) investigate the clinical implications of the empirical observation that 75% of milk-allergic children tolerate extensively heated milk in foods such as baked goods. These children have been observed to have milk-specific IgE directed at conformational epitopes rather than sequential epitopes. Heating (such as baking) disrupts the tertiary structure and consequently, reduces the allergenicity of milk proteins to which these children are sensitive. In contrast, children who are reactive to heated milk products have milk-specific IgE to heat-stable, sequential epitopes.

Kim et al. report on their findings from a clinical study of baked milk tolerant and baked milk reactive subjects, wherein baked milk tolerant subjects were advised to include baked milk food products in their diet on a daily basis, while baked milk reactive subjects were advised to practice complete strict avoidance. A comparison group, not initially challenged to baked milk products, was also observed over the study period.

Overall, Kim et al. report that initially baked milk tolerant subjects were 28 times more likely to become unheated milk tolerant than those initially baked milk reactive subjects, as compared to those subjects who observed strict avoidance. Baked milk tolerant subjects that received active treatment (that is, were able to include baked milk products into their diets) were significantly more likely to develop tolerance to unheated milk compared to the comparison group.

The authors demonstrate two important outcomes of their study: 1) baked milk tolerance is a marker of mild, transient cow’s milk allergy; baked milk reactivity implies a more persistent, severe form of cow’s milk allergy and, 2) the majority of children with baked milk tolerance that routinely eat baked milk food products will develop unheated milk tolerance at an accelerated rate compared to children prescribed a strict avoidance diet.

Kim et al. suggest that ingestion of baked milk products by tolerant patients is a safer, more convenient and cost-effective method of immunotherapy. They also comment that their results might be extrapolated to children with egg allergy in light of reports on heat-related changes in allergenicity of egg proteins.

We asked first author Jennifer Kim, from Mt. Sinai School of Medicine, to tell us about the implications of this work for future research. According to Dr. Kim, “These findings have provided the impetus for a more rigorously designed study that has been developed by our group to determine whether more rapid introduction of increasingly allergenic forms of baked-milk products in baked-milk non-reactive participants shortens the time until they tolerate higher doses of less heated milk and ultimately unheated milk.”

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