Sabrina Shannon didn't die from being kissed. She died from eating french fries that had something she was allergic to in or on them.

Yes, deaths do happen from allergies, but not from being kissed by your boyfriend nine hours after he eats something you're allergic to, which was the OP's point.

I have allergies to coffee, sucralose, and aspartame, and it's amazing how paranoid people have got. "Is it okay if I use sweetener?" they'll say, even though they're only adding the sweetener to their tea and we're using separate cups.

The point is: be aware, be educated, but don't be hysterical.