There are people that are *allergic* to onions and their kin. It's just about like being allergic to water.
BBC:
BBC:
Onions make me cry but not in the usual manner. I am allergic to them and their related cousins - garlic, leeks and chives. If I eat them I vomit or I get marks like spots or ulcers on my skin.
I was diagnosed in a hospital in Dublin about 20 years ago. Before that, I thought I just didn't like onions and I had naturally reduced the amount I ate - but I didn't realise I was allergic to them.