Archive under hives. Archive under hives.
ALL hives are at least partly related to storage of stress-effect in the hypothalamus.
The basic rule is that, if this is due to a food allergy, the more commonly one ingests the stuff, the more likely it is that one would become sensitive to something in it. Since there are many things in Ensure, this would be a good place to start. In the long run, though, the SR is the answer to the whole problem.