Thanks for the response Catlady. I probably should take one of them to the vet as you mentioned. Stinky, who has it the worst isn't my first choice to bring in though because she has the herpes virus and anytime she is put in a stressful situation the virus breaks out in full scale and she becomes quite ill. The last time I took her to the vet to have her anal glands emptied she was sick for weeks afterward from the virus. There is a vet that comes to the area I live in and makes house calls throughout the day to the community. I might find out her next date for visiting and line something up. I'll have to find out if she is able to do skin scraping etc.. while being mobile. Also, this way, she could have a quick look at all the cats and compare their symptoms.
In the meantime, I will keep them on bottled water and their usual food that they are used to eating.
I had been thinking the issue might have something to do with mites which is why I had considered using Revolution. But that could be something the mobile vet could look for as well.
I did think of one other thing earlier today that might be the cause. We have been painting inside our house. One room at a time and each time we painted one of the cats rooms, we would move them out of it and keep them out for 2 days and then put them back in after we had left all the windows open and really aired it out and when it smelled normal to us. But, maybe they are much more sensitive to it than we are and what we don't smell in the air, may be an irritant to them. I googled 'chewing paws' and found some information about irritating inhalents that can cause such a reaction. Thankfully, we are completely finished with all the painting. Just finished yesterday.