Unsolved breathing issues?

I have a 12 yr old with allergies, his testing involved these little plastic tines (not sharp or painful, he was 6 at the time) their grouped in 8's and dipped in different allergens and pressed to the skin after a few minutes, the areas either did nothing or raised up like a mosquito bite (allergic reacton), now his food allergy tests were needles (separate) and were not really injected but put in at a sideways type way on the back fleshy part of his bicep (I was present ans watched ths all) now it may be different for adults but I don't see how a blood test could check for all allergies. My son has like 12-13 mostly environmental, all those meds including over the counter and prescription did nothing for his symptoms now he has injections that started at once a week and has graduated to once a month and he's lost a allergy...and no he never sneezed.