I recently had same problem and posted on here.  My bloodwork also unexpectedly skyrocketed.  When doc sent online comment saying something like "you need to be eating gluten-free food" I was almost in tears because had been very careful.  Like you, went on a mission.  Narrowed mine down to Yasso yogurt mint chocolate chip bars (formerly had Certified Gluten Free label on package but learned now only on small boxes but not large boxes) or BJ's only mixed nuts without "may be processed on equipment that also processes ....wheat" allergy warning and said in big letters "A GLUTEN FREE FOOD."  I went off both and bloodwork drastically improved.  Still don't know if culprit one or both (will add one back in and test again).  Throwing out in case you're eating either of these.  I live in Pittsburgh and during appointment my gastro told me some U. of Pittsburgh students were having same problem.  They finally narrowed it down to liquid injected into chicken they were eating.  (Apparently to make it moist and/or plump.)  Understand how frustratitng it is when you're making all the sacrifices to be careful.  

Thanks for the reminder!

Thanks for the confirmation!  I decided to get it. 

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.