Potentially an allergy....which I have never really belived in....but let me explain.
I think some variation of the leaky gut theory is true. I also think skin prick allergy tests are pretty bogus. I have had some majorly expensive work done on plasma and it
brought some very interesing info to the mix......certainly showed more than the skin
prick.....I`ll bet if you could do a test on the villi you would learn that digesting this is difficult for your particular metabolism. A Heidelberg test might show you lots
about yourself...low stomach acid is way more prevalant than most know.
Stress lowers HCl in my opinion by depleting many nutrients such as B3 and perhaps even buffering minerals.