I Started With A Rash Just Above My Ankle Bone,

I started with a rash just above my ankle bone, now it is just a big red spot and it is getting bigger, It is smooth but real red and itches . I have been to the doctor and got several different creams and lotions, but not getting better. I do have diabetes. I do have dry skin. try to keep lotion on me. Now there are more dry itching spots showing up on my upper arms. calamine lotion seems to help the itching but does not heal the spot. Any information you can share with me I thank you. Violet