Previously it was thought that around three-quarters of children with milk and egg allergies would outgrow the condition by the time they start school, if not before. According to new research from the Johns Hopkins Children's Center, milk and egg allergies now appear to be more persistent and harder to outgrow.

Researchers followed more than 800 patients with milk allergy and nearly 900 with egg allergy over 13 years, finding that just one-fifth of children in their studies outgrew their allergy by age 4 and only 42 percent outgrew it by age 8. By age 16, 79 percent were free of their allergy.

Similar trends were seen in the egg-allergy group. Only 4 percent outgrew this allergy by age 4, 37 percent by age 10, and 68 percent by age 16.

The findings give credence to what pediatricians have suspected for some time: More recently diagnosed food allergies behave more unpredictably and more aggressively than cases diagnosed in the past. "We may be dealing with a different kind of disease process than we did 20 years ago," says lead investigator Robert Wood, head of Allergy & Immunology at Hopkins Children's.

"The bad news is that the prognosis for a child with a milk or egg allergy appears to be worse than it was 20 years ago" says Wood. "Not only do more kids have allergies, but fewer of them outgrow their allergies, and those who do, do so later than before."
Reports on the two studies appear in the November and December issues of the Journal of Allergy and Clinical Immunology.