First of all I eliminated all harsh soaps and switched to moisturizing soaps like Dove, Caress, or Tone.
Aveeno moisturizing
lotion with cooling menthol gives temporary relief with the rash, as does using the Aveeno Oatmeal baths ( helps a lot ). Some people use the Gold Bond Anti Itch products.
The best thing for relief from the itching is Atarax and it works well for many hours. However, you will have to have your doctor write a prescription for it.