I think labeling ingredients is a good idea. My dad had an odd one--garlic! One evening we visited his sister's family. We walked in the door, his face turned red, and he walked out. It turned out she was cooking spaghetti sauce without a lid on the pot. She covered the pot, opened the windows, and after a while he was able to join us. If he ate food with garlic in amounts too small to smell, in a little while he would vomit. This was most likely to happen when he ate garlic in foods we didn't expect to contain it, like stuffing. Our family recipes didn't include it.
When I had my first apartment. I went mad with garlic, throwing it into everything except desserts--but not if I was cooking for dad!