I have SLE, Fibro, Anti-phospholipid syndrome, rheumatoid arthritis, etc. Burning in the buttocks is completely normal for Fibro. Mine usually starts in the low back runs down the buttocks and sometimes even effects my legs. It's not fun for sure. My doc prescribed Soma 350 for break away pain when it's everywhere. I hope this helps.
thanks faith!!! i'll talk to my rheumy about it. how have you been?