I have had cats all my life, absolutely love them, and have pretty severe cat allergies. I have atypical symptoms too, so for me an allergic reaction is a massive sinus headache that becomes debilitating to the point I canāt be upright, general weakness, and nonstop vomiting for 6 - 12 hours. This happens to me at least once a month. (Though to be fair, Iām usually actually set off by other allergens, but they might not hit me as hard if I didnāt have the constant drain on my immune system from the cats.)
I saw a couple responses to this that had only half of the explanation of what actually sets off allergies? The allergen is in cat saliva, but with cats grooming constantly it pretty much covers their entire body. Cats have very light, fine dander that becomes airborne easily and doesnāt get filtered well (Iāve been told only paper filters are effective), which carries the allergens in the saliva right into our airways. If there is a cat in the house, you are breathing this in.
Things that help are the right air filter, keeping the cats out of the allergic personās bedroom, and supposedly washing your hands after touching them (which is ridiculous, I donāt do that, but I also canāt resist buring my face in their fur, which will probably kill me one day). I donāt know that brushing would becessarily help much (certainly not if the allergic person is the one doing it) as Iād think that would just stir up more dander into the air. But wiping down or, when possible, bathing cats is supposed to help.
Different cats do seem to set me off differently, but I suspect its a little more individual to both the person and the cat than the internet lets on. Iāve read that dark and longhair cats tend to be worse, but I have a black longhair manx that isnāt nearly as bad as his grey sister. They have very different coats and skin - eveything on her is finer, and she grooms a lot more, so she sets me off more. There are breeds that are supposedly hypoallergenic, but Iāve also heard that they arenāt 100%, or that they arenāt really at all. So I donāt know that I would invest in hunting down some rare breed hoping that it might not be as bad if its not a guarantee, you know?
I am on 2 daily pill medicines, 2 vitamins, and a nasal inhaler/spray (that I never remember to use, but every doctor has always told me are the very best thing you can do for your allergies) all just for my allergies. I also take an over the counter med regularly, and use a NetiPot when my symptoms start to get bad. Oh, and allergy shots. Those have helped a lot.
What Iām saying is that I have to do a LOT to fight off my symptoms, and they still interrupt my life at least once a month. Everyone reacts to things differently, maybe your housemate doesnāt have as severe of allergies as I do. But if theyāve never lived with them, would they know that for sure?
This is a huge commitment for someone with allergies to make. Your housemate needs to really LOVE cats to the point that they would be able to accept the negative effects on their health. They will be living with this 24/7. Living with a cat will definitely give them symptoms, thereās no way to get rid of them entirely. The best you can hope for is managing and minimizing them.
That said, if you guys still want to get a cat, thatās really exciting and great! Because cats are great. But donāt forget to think about the cat too - what happens to them if you try this out and then it turns out your housemate canāt live with having symptoms every day, or that their allergies are worse than they thought? So I would suggest that you look into fostering a cat first, so you can have a chance to try it out and see how they do. And in the mean time, you help save cats by freeing up space in a shelter! :)