It looks like it is possible to overcome food allergies:
First, youngsters spent a day at the Duke hospital swallowing minuscule but increasing doses of either an egg powder or a defatted peanut flour, depending on their allergy. They started at 1/3,000th of a peanut or about 1/1,000th of an egg, increasing the amount until the child broke out in hives or had some other reaction.Then the children were sent home with a daily dose just under that reactive amount. Every two weeks, the kids returned for a small dose increase until they reached the equivalent of a tenth of an egg or one peanut — a maintenance dose that they swallowed daily.
After two years, four of the seven youngsters in the egg pilot study could eat two scrambled eggs with no problem, and two more ate about as much before symptoms began, researchers report in the January edition of the Journal of Allergy and Clinical Immunology.
In the peanut pilot study, yet to be published, six of the children challenged so far could tolerate 15 peanuts, Burks says; Elizabeth’s limit was seven.