If you need to bathe, DEFENDEX shampoo is soothing. I like to use it because it is nontoxic. If there are any fleas it will help you to spot them.
DERMA-IONX is helpful for a variety of skin conditions reducing inflammation and itchiness. It is an oral homeopathic product which stimulates the enzyme systems in the body that aid the skin and helps with assimilation of nutritional components in diet and supplements. The supplements I use along with it include Probiotics and Omega 3,6,9. The OMEGA 3.6.9 is especially helpful for soothing the skin. These supplements together with DERMA-IONX can produce a synergistic response. I would also suggest that you give your dog only filtered water for drinking and bathing if your water contains chlorine or fluoride.
For the dietary modifications you might want to try a grain free diet and feed cooling foods when the skin is hot and inflamed according to Chinese food therapy. Fish and turkey are considered to be cooling so would be better choices than chicken or lamb which are warming. Of course if your dog has a food sensitivity to a particular food do not give that food. (Beef is neutral.)
What are you doing to get rid of the fleas in your house, car, yard, and other pets? Once you are flea free you should have a stool sample checked for tapeworms. If positive then it is important for your veterinarian worm your dog.