Skin rash and brachioplasty

I have a large amount of skin hanging off my arms to the point that I have 3 rolls or creases on them ( I have lost 152 pounds). I have had no luck at getting a rash, which I know sounds funny, but I have to have a rash to have surgical procedures covered, which I am sure you all know about. I have heard of using certain products to create a rash, has anyone heard about this method or tried it? Any input would be appreciated. thanks