"Will he grow out of it?" is a question I get a lot. The short answer is no. The long answer is, well, read on.
It's fairly common knowledge that children often grow out of food allergies. Eosinophilic Esophagitis isn't a typical food allergy. Chances are that Oliver has "normal" IgE mediated food allergies* that don't affect his EoE and others that do. For example, blood tests have told us that Oliver has an awful lot of IgE antibodies when milk is introduced to his system. This very likely means that he has an IgE mediated allergy (I say very likely since these blood tests aren't always accurate, especially for young children). Since drinking milk (or even just touching milk) gives him an eczema rash, we tend to think that's a true allergy for him. But, milk may not trigger his EoE. If it turns out that it doesn't trigger the EoE, he could very well grow out of the allergy. If it does trigger the EoE, he will always need to avoid milk.
How do we know what triggers the EoE? First we have to get to a point where we've eliminated everything that might possibly cause a reaction. Hopefully he will have another endoscopy before the end of the year. Either it will be clear (meaning no eosinophils) or not clear. If it doesn't come back clear, then we need to eliminate more foods (while still keeping him off of the ones he's already off). If it comes back clear we know we've eliminated the offending foods and we can start to add some back because may have also eliminated foods that really aren't triggering his EoE. If we are able to add a food back with no reaction from him (we'd probably need another endoscopy to know for sure), then that food can go on his okay list.
Basically it's a long game of trial and error.
Clear as mud, right?
*IgE antibodies are produced when immune cells encounter the food, the antibodies see the food as an invader and trigger an allergic response. This itself has nothing to do with EoE other than the fact that many patients have IgE allergies along with their EoE and testing for IgE allergies can be a good (and much less invasive!) way to guess what EoE triggers might be. For some people, their IgE allergies ARE their EoE triggers straight across the board, but I don't believe that is very common. (last paragraph updated 12-13)