Very good post on a subject that is wildly misunderstood by both parents and many physicians. I see children very frequently who have been on very restrictive diets based solely on what the allergist told them their food allergy testing revealed, some who have had very poor growth and nutrition as a result and who actually have no problems at all with the foods they were told to avoid.
The fundamental problem, I think, is that doctors either don’t understand or can’t seem to explain the difference between sensitization and allergy. None of these tests can actually test for allergy—they test for sensitization, which is different. We gloss over that distinction, and end up giving out bad advice. People should not be told to avoid food based on the results of allergy testing alone.
Bottom line: if you child eats a food without having a reaction, he or she is not allergic, and you should not do any testing for that food as a potential allergen. You should never do broad panels of “allergy tests”—they’re much more likely to mislead and confuse than to give useful information. Any food allergy testing that is done should only look at foods that seem to have caused reactions in the past, and even then any positive testing should be confirmed by what’s called an “open challenge.” Under safe conditions, usually under an allergists’ care, give the child some of the food to eat to see what happens. That’s the only real way to “test” for allergy.