SAN FRANCISCO -- Kids who can't tolerate milk but can pass the "muffin test" without symptoms may outgrow their allergy faster if they raid the cookie jar on a regular basis to keep baked dairy in their diet, researchers found.
Children who did not react to milk that was heated sufficiently to change the shape of allergy-causing proteins had a 27.8-fold greater likelihood of losing the allergy altogether within three years, according to Dr. Jennifer S. Kim of Mount Sinai School of Medicine in New York City and colleagues.
Among such children, 60 percent could drink a glass of milk without problems after three years compared with just 9 percent of those who couldn't tolerate what the researchers referred to as baked-milk products, the group reported here at the American Academy of Allergy, Asthma & Immunology meeting.
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Tolerating baked milk may simply be a marker for less severe milk allergy that is more likely to resolve on its own, Kim told MedPage Today.
However, the allergy resolution rate appeared accelerated in those who incorporated waffles, cookies, and other baked goods made with milk into their diet.
Kids who found out they could eat such foods and then did on a daily basis were 16 times more likely than those who followed a strict elimination diet to have overcome their allergy and been able to drink a glass of milk without problems after three years.
It's possible that eating heat-altered milk proteins regularly acts as a form of "natural immunotherapy" to retrain the immune system not to attack unaltered milk protein, Kim suggested in an interview.
Indeed, the immunologic response in that group as measured by milk-specific immunoglobulin G4 and basophils and skin prick wheal size showed changes that "looked very much like someone who's gone on some form of immunotherapy," co-author Dr. Hugh A. Sampson of Mount Sinai explained at a press conference where the results were discussed.
The group had discovered in 2008 that 75 percent of milk-allergic kids challenged with a waffle could eat it without an allergic reaction. The same proved true in challenges with muffins and, for some, the gold standard -- pizza.
Of that initial group of 100 kids studied, 88 continued to be followed for a median of 37 months through food challenge tests with progressively less heated forms of milk at varying intervals of anywhere from six to 54 months.
The majority of the 65 who initially tolerated baked-milk foods went on to become tolerant of unheated milk (60 percent) or at least baked cheese (28 percent).
Only 12 percent still strictly avoided all dairy at three years despite having been counseled to incorporate baked milk into their diet.
The picture differed for those who were initially reactive to the waffle or muffin. Of those, only 9 percent went on to tolerate unheated milk and 13 percent baked milk or cheese.
Another 60 kids matched for age, sex, and milk-specific immunoglobulin E as a comparator group were followed for a median of 40 months.
These controls were 2.8 times less likely to become tolerant of baked milk or cheese and 5.8 times less likely to become tolerant of unheated milk than both other groups combined who had routine food challenges as part of the study.
Regarding safety of baked milk for the children who could tolerate it, growth and intestinal permeability followed for 12 months showed no adverse effects.
Eosinophilic esophagitis developed in two active-group children (2.3 percent). One couldn't tolerate baked milk and had been strictly avoiding milk at the time of diagnosis. The other developed the esophagitis after successfully downing unheated milk in the food challenge but didn't improve after all forms of milk were eliminated from his diet and milk was reintroduced safely.
In the comparison group, the rate of eosinophilic esophagitis was 8.3 percent despite all the children being on a strict milk-avoidance diet.
Despite the apparent safety of this approach, Sampson and other leading allergists have warned families not to try baked-milk food challenges at home.
Food challenges in the study were done under medical supervision in carefully controlled conditions so that any severe reactions could be treated quickly before serious harm occurred.