Seventy-five percent of children with cow’s milk allergy will be able to tolerate it if it is heated extensively, according to a report in the Journal of Allergy and Clinical Immunology.

Children with persistent milk allergy produce antibodies that react against specific milk proteins that their immune system recognizes as foreign, according to Dr. Anna Nowak-Wegrzyn, from Mount Sinai School of Medicine in New York, and her colleagues. Children who have outgrown their milk allergies still have milk-specific antibodies, but the specific milk proteins that trigger this reaction can almost entirely be destroyed through exposure to high temperatures. The researchers therefore reasoned that children with milk allergy might tolerate milk if it were extensively heated.

In the study, 100 children were given various milk amounts of milk. First, baked muffins and waffles containing heated milk protein were given. If these were tolerated, the child was then given unheated milk. The children who could tolerate heated but not unheated milk continued to receive heated store-bought or home-baked products containing milk for 3 months and were then reassessed.

Overall, 68 children were able to tolerate heated milk, but not unheated milk, 23 reacted to heated milk, and 9 children were able to tolerate heated and unheated milk, the findings show.

Compared with the other groups, those who reacted against heated milk had a greater reaction to skin prick tests and a higher level of antibodies directed specifically against casein and milk. Moreover, the symptoms in response to heated milk in these children were more severe than those observed in children who tolerated heated but not unheated milk.

The subjects who were given heated milk for 3 months had smaller reactions to skin prick tests and a higher tolerance for casein than they did at the beginning of the study. No changes were observed in other areas of the immune system.

If these findings are confirmed by other studies, the approach to diagnosing and managing children with milk allergies should change, the authors conclude. “Allowing ingestion of heated milk products will dramatically improve the quality of life for the majority of subjects with milk allergy by vastly increasing the variety of food products they are able to consume.”

SOURCE: Journal of Allergy and Clinical Immunology, July 15, 2008, online.