Some people that I know are not worth explaining anything to them. I am not allergic to anything physically. I know one person though that makes me sick, sick in the heart, sick trying to figure out what the heck they are doing, sick to my stomach, fearful, angry, feeling invalidated, treated unjustly, falsely accused, angry. I would not usually explain why or how, I am allergic to this person. If I were to say, "I'm allergic to this person", most people would get the subtleties of language, recognize it is not a physical allergy in the sense of hives, vomiting, throat closing up, problems breathing and take me to a hospital. That I do not like the way I'm treated by this person, is enough for me to say, no thanks. I might have to start saying, "I'm allergic to this person". And just leave it at that.
I am also not a picky eater, I like almost everything. There are people here brought up in homes where their parents forced them to eat things they didn't want to eat. Recognize for what it is, a violation of their preferences and who they are. Being forced to eat food can leave a lasting impression upon a person and they may choose to find a way around a conflict of being forced to eat something, as "I'm allergic" as that shuts down the conflict. If someone says they are allergic to something, they are either stating a health issue or a preference. I accept this.
I realize some people here must have absolute honesty and require this honesty, but, really, is it any business of yours, their medical records, or is this a court of law? This is a social forum to learn and share, it is neither anyone's business about another person's medical records and this is not a court of law either.