How do you tell the difference between someone who THINKS they have an allergy, and someone who ACTUALLY has one, so you have the opportunity to dislike them?
OK, I was being polite: someone who CLAIMS to have one. Had a friend who claimed an extremely severe cat dander allergy - couldn't even walk past a house where there was a cat - then, at a party, discovered after many hours that two cats were under the sofa they were sitting on, but only when they emerged. No sneezing, coughing, etc. UNTIL the cats appeared, then .... Found out the cats usually slept on the sofa.