Hello,
If it is raised sacra then it can be due to hypertrophic scar or keloid. You can upload some pictures in your profile so that it helps in understanding your condition better and I can help you in a better way.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
I have some photos if you're interested in helping me.