Are you eating anything with vanilla in it? While I don't get sick like a real glutening, I itch! It is the kind of vanilla that is supposed to be safe for us. Dairy and soy also give me gluten like symptoms, itching, dry skin, hair loss, sleep problems, etc. So, no gluten, including vanilla and white vinegar, no soy and no dairy... skin and hair does great and no itching.
Everyone is different. If I get cc, I have different reactions everytime, plus some of the old ones as well. And the reaction/healing time is different everytime as well. I don't know what I think about being super sensitive, I react with joints hurting and skin problems when I try using things such as MacCormick's Vaniila that is labeled gluten free, or white vinegar which is supposed to be safe. I am 4 years into this journey, I only eat what I make, and then the ingredients have to be 100 percent gluten free. I was in pretty bad shape four years ago, and now at 62, I feel great, but only because I am very, very, picky about what I injest. Whole foods and a few of the certified gluten free foods, no dairy, no soy, works for me!
I am gluten intolerant, my first symptoms were nerve related. Went to doctors, specialists, they ruled out everything, but couldn't tell me what was causing my problems. I went gluten free on the advice of a neighbor, and the nerve problems dissappeared along with about 300 other symptoms...well maybe not 300 but close. Took awhile but am feeling great now with no symptoms. If you want a definite diagnosis, remain on gluten to be tested. I had an endiscope, and gene testing, negative results, was too sick to go back on gluten for blood test. I stay away from resturants and other people's cooking and cook mostly with whole foods and I stay healthy!
If his health is still declining, I would go completely WHOLE foods, only. I would also suggest no dairy and no soy. I know how having a sick kid can make you feel, my prayers and thoughts are with you.
I used a knife my husband had spread his jam with, I used it to cut a banana, was sick 20 minutes later. I also have been using Diamond brand walnuts in my muffins without any problems. One morning for breakfast, had my usual muffin and twenty minutes later I was sick. Read the label, "nuts are processed on same lines as wheat, other nuts etc. I get sick with anything that shares equipment, I am learning to read labels everytime I purchase something.