Cat has bald spot and is very affectionate all of a sudden

So I noticed a bad spot on the back of my cats neck and I noticed another very small crusty spot on his neck a few days later. Then I looked at my dog and he also has a bald spot on his shoulder. This was about two weeks ago. I've done some research and it seems like it's scabies. They've most likely had these spots for more than two weeks, yet no one in my house has any sign of scabies. Also, they don't interact with other animals so if this is mange where did it come from and why hasn't anyone contracted it from them? One last thing I wanted to add is that my cat has become more affectionate than usual and I have a bad feeling. Do you think he has some kind of immune issue that's causing the skin problems?

It could also be ringworm (a fungus infection that humans can get, too) that your dog picked up outside and gave to your cat. Either way, both need to be seen by a vet and put on meds before the situation gets worse.