The main thing that cats have that upset some people is a protein called Fel d 1. It comes from the sweat glands in cats.
If you are allergic to cats but you decide to keep one in the house then you and your family will need to do the following things to remove the upsetting protein from your house.
- Install an air filtration unit in your house to filter the allergens from the air. (This might help reduce other allergy problems, too.)
- Reduce the number of carpets in your house. (Even careful vaccuming won't get rid of all the allergen from the carpet.)
- Wash your cat once a week!
The best way to wash your cat is to immerse him or her in a bath of warm water with a weak detergent in it. Make sure you actually dunk your cat completely underwater.
Then rinse your cat in a bath of clean, warm water.
Your cat will hate this but will gradually get used to it. Giving your cat kitty treats after the awful bits will help.
I hope it helps you, too.