Hello I have the same skin rash on my legs and arms. The doctors say its just a allergy. Here is what my doctor tells me to do, when taking a shower tone down the temperature just a little bit because hot water aggrivates the rash. as soon as you (pat dry) your skin  apply a lotion that contains cocoa butter and let it soak into your skin before getting dressed. The lotion I use is made by Queen Helene Cocoa butter hand and body lotion. One thing you must stop doing is scratching the rash I know its hard to do but believe me scratching it makes it worse not to mention it burns like crazy when putting on any lotion. Also take a small bottle of lotion with you for flare ups. One thing that makes the rash worse is STRESS.  DO NOT use a lotion, soap etc with a strong fragrance, strong frangrances aggrivate the rash. At times you will need to change lotions due to it seems not to work as well as it did before, but you can use it again in a couple of months. I hope this helps releive the pain and itching for anyone that suffers with this rash.