Sounds like your dog might be suffering some sort of allergic reaction to the new home. If this started after your move, and only specifically after the move, I suggest you find a vet somewhere in your area and bring her in for an allergy test panel. This is a test that most vets will send away to a lab and they'll be able to figure out exactly what your dog is allergic to. Of course, that's not to say that she doesn't have some sort of other under-lying health issue that your vet hasn't been able to narrow down yet. If she is in pain or if the rash seems to be bothering her, you can try using an oatmeal based shampoo on her. The oatmeal seems to have a cooling/comforting effect on skin issues and it might be enough to keep her comfortable for a little while. The oatmeal shampoo can be found at any petstore or places like WalMart, Target, ect.

I understand your concern about the cost, however if you were to suggest the allergy panel to your vet, then perhaps he could narrow down exactly what your dog is allergic to. It could be something as simple as the type of dog food you're feeding her, or it might be something big like the carpeting in the mobile. Please don't get discouraged. I'm going to do a little more research (I have an alternative medicine vet that I'll be seeing on Monday) and see if there's something like tea tree oil that you can use on your girl. Don't give up just yet!!