Allergic esophagitis triggered by milk may not require complete avoidance, according to a small study that found most such patients could tolerate dairy if it was baked into bread or other foods.
Nearly three-quarters of children who tried baked goods that contained milk had no signs of symptoms or inflammation in the esophagus, , of Massachusetts General Hospital in Boston, and colleagues found.
Those who did have reactions generally developed only mild symptoms -- mild abdominal pain in one case and trouble swallowing in two, the researchers reported in a research letter in the November issue of the .
These findings agreed with those of a prior study that found about 75% of children with another category of milk allergy -- immediate immunoglobulin-E (IgE)-mediated hypersensitivity -- could tolerate muffins, cakes, and breads containing milk.
Staying away from milk entirely is difficult because it is found in many processed foods, , and his fellow editors noted in highlighting the study in the journal's Editor's Choice section.
"The ability to add baked milk products back into the diet could have a significant effect on adherence to the diet, quality of life, and nutrition in patients with cow's milk-mediated eosinophilic esophagitis," they wrote.
While agreeing that the eosinophilic esophagitis results were promising, Hesterberg's group cautioned that their study was small, with just 15 patients, and retrospective.
"Our results must be validated in a prospective study before generalized application in clinical practice," they pointed out.
There is a plausible mechanism for why individuals would react to milk but not after it had been baked, they explained: heating changes the shape of the allergy-triggering protein in milk, so that the immune system doesn't recognize it as the same threat.
Prior studies have even suggested that eating baked milk may act as a form of immunotherapy to help children outgrow their allergy to uncooked milk.
Experimental assays have been able to show prospectively which kids are likely to pass the "muffin test," but experts have suggested simply trying it in the office.
Hesterberg's group identified all 15 patients (ages 6 to 17) at their center with eosinophilic esophagitis unambiguously caused by cow's milk who tried eating baked milk for at least 6 weeks and who had endoscopic follow-up to show how they did.
Their diet had to be documented to include at least three or four servings per week of home-baked or store-bought baked goods containing milk, like bread, muffins, cakes, and brownies.
"Ingestion of cheese, even if baked (e.g., pizza), was not regarded as baked milk for the purposes of this study," the researchers pointed out.
All the patients stayed on proton pump inhibitor therapy twice a day through the final in-office challenge.
At that challenge, 11 patients (73%) maintained histologic remission with fewer than 10 eosinophils per high-power field. Nine had no measurable eosinophil reaction at all in their esophagus.
Ten had normal endoscopic findings. One tolerated baked milk without symptoms but had abnormal endoscopic findings regardless of dairy elimination.
One of the patients without any eosinophil reaction tried a nonbaked milk challenge but failed and thus stayed on baked milk only.
Notably, commonly used allergen tests -- skin testing, patch testing, peripheral eosinophilic count, milk-specific IgE testing, and total IgE level -- did not predict baked-milk tolerance or reactivity.
Other characteristics like age, sex, duration of disease, and other atopic disorders didn't differ by baked-milk tolerance either.
Disclosures
The study was supported by the Demarest Lloyd Jr. Foundation.
Hesterberg reported that his institution received money for the study from that foundation.
Primary Source
Journal of Allergy and Clinical Immunology
Leung J, et al "Tolerance of baked milk in patients with cow's milk–mediated eosinophilic esophagitis" J Allergy Clin Immunol 2013; 132: 1215-1216.