One neurologist thought I might have Lupus based on a rash on my face, while the other thought MS. I found an interesting website that has a comparison chart for MS, Fibro, and Lupus:
~ Symptom Cross-Reference Chart ~
http://www2170.ssldomain.com/msakc/Articles/MSFibroLupus.htm
I would be interested in any other autoimmune comparison charts, if anyone knows of one.