Not sure if this is what you mean, but my DS6 has severe MFA (nuts, eggs, sesame, shell fish, etc.) possible ADHD and our developmental pediatrician suggested he may be reacting to certain foods that he is not technically allergic to but that nevertheless irritate his system. He also has trouble controlling his emotions sometimes. I sincerely think that SOME kids (not all) with MFA also experience developmental issues related to foods they are not allergic to but nevertheless create other symptoms.
If you are interested in more information, check out Feingold.org. I actually don't endorse most of Feingold, but thought its premise is interesting.