It's an odd business. I have a few sensitivities myself, but none immediately fatal. Can't eat this, can't eat that, can't breathe this, can't take that medicine... just makes me into a reluctant fusspot, and there's no sympathy for such boring inadequacies.

There does seem to be an increase world-wide in allergies. As a kid, I knew a couple of kids had hay fever, and that was about it. (Now I react to several types of pollen and the hairs off the back of lime tree leaves.) Someone somewhere must be researching this. If sensitivities are increasing in severity and scope, how will it be in another generation or two? Needs sorting, along with all the other things.