Are there any pain scales which measure how much of the body is in pain? Are there any pain scales which talk about the extent of pain, i.e. how much of the body is in pain?

I'm in the process of trying to work out whether several lesions, hurt with the same intensity as a single lesion of the same severity.
I can tell you this, in RA the addition of swollen joints in a flair up increases the pain until your number exceeds so many than the pain levels. In arthritis of the spine, spondylosis seams to stay the same as the gradual increase of more arthritic vertebra increases. But when spondyolithisis increased from one to two the pain was double. (The movement forward or sideways of the vertebra) That's all I know,10 years experience.