Many kids may not outgrow cow's milk allergy

Cows graze in a field near the eastern German village of Pudlitz, July 30, 2007. The sign reads 'Our Milk'. Cow's milk allergy persists longer than previously reported, and the majority of children may retain the sensitivity into school age, study findings suggest. (Fabrizio Bensch/Reuters)NEW YORK (Reuters Health) - Cow's milk allergy persistslonger than previously reported, and the majority of childrenmay retain the sensitivity into school age, study findingssuggest.
"The old data saying that most milk allergy will be easilyoutgrown, usually by the age of 3 years, is most likely wrong,"Dr. Robert A. Wood, at Johns Hopkins University School ofMedicine, told Reuters Health.
He and colleagues found that just 19 percent of childrenallergic to cow's milk outgrew their allergy by age 4.
Moreover, Wood added, "some children will outgrow theirallergy into their teenage years, which was previously thoughtto be unlikely." His team found that by the ages of 8, 12, and16 years, 42 percent, 64 percent, and 79 percent, respectively,had outgrown their milk allergy.
Wood and colleagues reviewed the clinical history of 807children who were treated at a pediatric allergy clinic formilk allergy. Children were considered to have acquiredtolerance if they passed a skin prick test, reported drinkingmilk without a reaction for the last years and had cow's milkassociated immunoglobulin E antibody levels less than 3 kU/L.
"The higher the level of immunoglobulin-E antibody, thestronger the allergy," Wood said. "Therefore, higher levels notonly confirm the allergy but make it less likely that theallergy will be outgrown, or at least that it will take longerto outgrow," he added.
They also found that children with asthma and allergicrhinitis had a decreased likelihood of developing tolerance tomilk products.
In this population of highly allergic children, 91 percenthad at least one other food allergy, most commonly to eggs andpeanut.
The most common symptom of milk allergy was skin-relatedreactions, affecting 85 percent, followed by vomiting, diarrheaor another gastrointestinal reaction in 46 percent; wheezing,cough or difficulty breathing occurred in14 percent; and nasalcongestion or other upper respiratory symptoms were seen in 6percent, the investigators note in the Journal of Allergy andClinical Immunology.
Wood and colleagues suggest their findings be corroboratedthrough similar studies in a more general population ofchildren with milk allergies.
SOURCE: Journal of Allergy and Clinical Immunology,November 2007.