A typical CYA response--since they don't label it that way they don't test for gluten, thus can't guarantee it's gluten-free, even though no gluten ingredients are used in the product.
I understand your immense frustration after 17 years of excellent management; it's incredibly disorienting to have your numbers spike without a clear cause or physical symptoms. Given your thorough investigation, the Crunchmaster crackers are a very plausible culprit, despite their certification. Certification ensures gluten is below 20ppm, but if you are consuming them daily, even that tiny amount could theoretically accumulate over time to cause an immune response (elevated IgG) without triggering your acute symptomatic response (which is often IgA-mediated). Since your son, the perfect control subject, doesn't eat them, this is an excellent hypothesis to test. I would recommend a strict elimination trial: remove the crackers completely for 4-6 weeks and then re-test your IgG levels. If the numbers drop significantly, you have your answer. Other less obvious sources to consider if the crackers aren't to blame include any other new packaged goods (spices, nuts, chocolate, supplements), a change in the recipe of a trusted product, or even lipstick or toothpaste. Your methodical approach is exactly what will solve this mystery.
When using daily med to look up prescriptions, is there a way to filter ingredients such as gluten or wheat? I usually take only a couple of drugs but since I’m having surgery, I have 5 new ones to take for a short time post-op. Thanks!
For non prescription drugs, Walgreens has a line called Free&Pure that has gluten free written on the packaging if anyone is interested.
Dr. Jean Duane published a book on Celiac.com, and although all chapters are worth reading, there are some that cover this perfectly. Here is the link to the 1st chapter:
This chapter and others cover this topic well: