Canon ones, (with proof):
(It even has a front pouch to place an actual cat, if you so desire.)
"Oh, I can't. I'm allergic."
"It's got soap on it! I'm allergic to soap, you (beep)!"
"You think you know someone and then WHAM! Out of nowhere... they fill your apartment with feral cats?! And now you're somehow responsible for the vet bills? You've got to give them away, but despite your cat allergy, you've endeared yourself to them, especially to Mrs. Snuffles... more like Mrs. Sniffles! ...Because of the allergy."
So, for the others, my guesses for allergies are:
Logan: Allergic to bullshit
Janus: Allergic to society
Virgil: Allergic to makeup remover