It is very important to tell ALL your Drs about
ALL you diagnoses and treatments. Otherwise they may be advising you to do things that are contra-indicated by your other issues.
It does sound like you have Lupus or a connected tissue disease. Drs generally use Cellcept, Imuran and/or MTX to treat these, along with Plaquenil. It is impossible to know ahead of time which of these 3 might help us, it's basically trial and error to see which we respond to. The order in which they are tried is really up to the Dr's preference - sounds like you Dr prefers MTX.
I'd suggest getting ALL your symptoms and ALL your treatments on one piece of paper, then going over it all with your rheumy. Maybe he will still suggest MTX, maybe not.
Lynnwood, Lupus & Sjogren's Moderator, Dx: 2002DIAGNOSING LUPUS & HW's LUPUS 101
"Life is far too important to be taken seriously." - Oscar Wilde