I became allergic to cats after playing with a very fluffy long haired cat - eyes swollen up so bad couldn't actually see. Never was allergic to anything before.
That was years ago and I've learnt to deal with it - have to be careful, no major cuddling, wash hands afterwards, remember not to put head on sofa pillows as they've slept there etc and if all else fails anti-histamine tablets and eye drops are great. But I'm an adult and I'd rather deal with the faff because I love my babies to bits and I think they're worth it. But I'm an adult and people are paranoid when it comes to kids and would rather take the animal away than learn to deal with it, though with asthma it can be unfortunately the only option.