My ds had extreme allergies as well. He would react by having seizures. There was a point when there was almost no food he could eat and was having so many seizures we really thought he might die. He lost all motor skills, all development and at 2 1/2 he was like a newborn.
We did NAET It was the miracle that I believe saved his life. It was amazing. We saw immediate results and now he can eat anything, anywhere. It took time, money & faith but in the end he was finally well. It was incredible.
There are many amazing stories in the book, "Say Goodbye to Illness" which was written by the founder of NAET. The book also describes the technique. It is very safe & effective.
We decided to treat our son using other means than the medical route. It was a difficult choice and caused a lot of concern for people, but my heart told me to search elsewhere. If that's your choice too, follow your intuition. There are lots of things that may help. NAET worked for us and it may for you, if not, find what does. Good luck to you!