You should take your dog to see your veterinarian if there is an open wound. You should also check for any signs of fleas. One flea bite can start the process similar to what you have described.
You might want to look at some of our products to help the skin. DERMA-IONX which is an oral homeopathic product stimulates the enzyme systems in the body which reduces itching and inflammation, promotes healing of the skin and helps with assimilation of nutritional components in diet and supplements. The supplements I use along with it include probiotics, Omega 3,6,9 and vitamin C. Together with DERMA-IONX it produces a synergistic effect. I would also suggest that you give your dog only filtered water for drinking and bathing if your water contains chlorine or fluoride. If your dog is not allergic to these protein sources you might try fish or turkey since these are considered cooling according to Chinese food therapy. You would want to avoid chicken or lamb which are warming for the skin that is already too warm.
Please feel free to contact us again if you have any other questions or if you get a diagnosis then we can make some additional suggestions .