Just wondering what do you clean your house with (Windex, Lysol, Pledge....) if you use these you may want to try just vinager and water. His skin may be having a reaction to the chemicals in the comercial cleaners. Even wash his blankets, food bowls and toys in Vinegar and water.
Also do you feed him in plastic bowls? If you do you might want to change to Metal or ceramic because they are not porus and do not hold bacteria.
You may also want to find a holistic vet one who uses all natural methods.

Here is a article on dogs with food allergies that was very helpful when My Fizzy got all ichy. http://allergies.about.com/cs/canine/a/aa091800a.htm

I hope this helps you and Jasper.