I Am A Diabetic And Have Recently Experienced Intense Itching

I am a diabetic and have recently experienced intense itching on my left arm between my elbow and shoulder. The itching is so bad that I would like to tear off my arm. I have put a cold wash cloth on my arm and bought an anti itch cream with cortisone in it - applied and have relief temporarily. My arm burns, is slightly reddish in color and feels like it has a fever in it. Besides going to the doctor is there anything I can do.