I don't remember if those two studies said allergy or sensitivity. Or possibly even intolerance, though you'd think that would just mean you can't digest it and it either comes up or goes through relatively unchanged. I had not heard of the distinction you draw and don't understand it.*
Anyway, I presume the studies were talking about a measurable physiological response that could be tested for simply and quickly, without requiring a behavioral assessment, or it wouldn't make sense in the context of the reports.
*Somebody I know, NT, reacts badly to wheat gluten. A little bit, he becomes stupid, grouchy and withdrawn. If he eats more, he'll behave that way and complain of a headache. Even more he will develop a fever and become visibly flushed. So is this an allergy, or a sensitivity? I understand it to be a common reaction to the substance. I bet if I played with him, some pastries, and the blood-test machine at my old job, I could watch his histamine levels rise (along with his ill temper, and my own). Wouldn't that make it an allergy in spite of the fact that most of the time his reaction to wheat is behavioral?