It is really handy knowing about histamines and antihistamines. My son recently got diagnosed with a couple of severe food allergies and I really wanted to know how histamines and allergies are related. I think it is tough to avoid getting histamines into your system, especially when so many things are produced in the same factories. It still amazes me how sensitive some people are.
I think one of the best things you can do if someone you love has a particular allergy is to just keep the product out of the house totally. There is too much of a chance of them getting sick.