A new study finds that children who are allergic to milk may be able to overcome their allergy by drinking increasingly higher doses of milk.
In the study, researchers followed up with 18 children aged 6 to 16 whose symptoms had eased or gone away during a 2008 study by researchers at Johns Hopkins Children’s Center. In that study, the researchers reported that children with a severe milk allergy could “retrain” their immune systems to tolerate milk and other dairy products by gradually consuming higher doses.
When 13 of the 18 children returned to the clinic up to 17 months later, six continued to have no reaction after drinking 16 ounces of milk, twice the highest amount tested in the earlier study. Seven children had mild reactions, including itchy mouth, hives, sneezing and stomachache after drinking less than 16 ounces.
The researchers also followed up with three children who could not drink more than 2.5 ounces at the end of the prior study. All three continued to drink milk daily with only mild reactions, and two were able to drink more than 2.5 ounces with few problems, the study authors found.
The study was published in the Journal of Allergy and Clinical Immunology.
One key to keeping the allergy at bay seems to be regular consumption of milk and dairy products, according to the study.
“We now have evidence from other studies that some children once successfully treated remain allergy-free even without daily exposure, while in others the allergies return once they stop regular daily exposure to milk,” said senior author Dr. Robert Wood, director of Allergy & Immunology at Johns Hopkins Children’s Center. “This may mean that some patients are truly cured of their allergy, while in others the immune system adapts to regular daily exposure to milk and may, in fact, need the exposure to continue to tolerate it.”
The researchers also tested for milk allergy using skin-prick testing, a standard food allergy test. Between eight and 15 months post-study, seven children had no reactions. Blood levels of milk IgE antibodies, which indicate allergy, slowly decreased, while IgG4, an antibody that indicates immunity to an allergen, rose. The study authors also found that the prevalence of reactions continued to decline over time.
Milk allergy is the most common food allergy. In those who are allergic, milk proteins cause the immune system to overreact, bringing a cascade of symptoms that can range from hives, itching, swelling and vomiting to anaphylaxis in the most severe cases.
