Sounds to me like you are bathing your dog too often and could be causing some of the itching. Dogs shouldn't be bathed that often unless there is a specific reason for it. "just because" isn't good for the dogs skin. Dogs skin is desinged to be self cleaning, as is the hair coat. Shampooing, even with a so-called moisturizing shampoo, is going to be very hard on the dogs skin. Think about when you wash your hands too often, they get dry and chapped and you start having to apply artificial moisturizures. That is the same thing that happens to your dogs skin when bathed too often. Dry, flakey, itchy and tight skin. Then the skin starts to over produce oils to make up for the stripping that the soap does. Then you get a greasy coat that attracts dirt instead of repelling it. Its a bad cycle.
If you are bathing the dog so often because of a strong "doggy odor" you can blame the food the dog eats most often. Dogs have a smell but it should be light and clean smelling not heavy and musky. Find a better quality of food that your dogs system reacts well to and I can tell you her odor will decrease a lot.