I used to do this with Aiesha. All you need to do is get an old pair of tights/pantyhose, cut off a piece, fill it with some oatmeal (about 3 or 4 tablespoons for good effect) and tie up the open end. Then, hang it under the tap when the bath is running. The water goes milky white and becomes really soft. The skin gets moisturised and the itching stops. Also, you can use the oatmeal "sponge" over the body to get some more of the goodness onto the skin.
Hope that helps.