From what I gathered, auto immune disorders are pretty common in people with candida overgrowth. I was diagnosed with polymiositis, but am waiting for a second opinion on the diagnosis and therapy (usual therapy for this is harsh dose of corticosteroids which, among other things, suppress your immune system).
I am not an expert or a doctor, but logically, for the candida overgrowth to occur, an immune system must be compromised. Then candida suppresses it even further and opens the door for other auto immune diseases. Then you get stuck between the rock and the hard place. You must suppress your immune system to treat symptoms of the auto immune disease or you strengthen it to try to get rid of the candida overgrowth in which case your own immune system attacks you even harder.
For now, I am controlling the symptoms somewhat with omega3, vit D3 and avoiding inflammatory foods (containing omega 6 etc.) until I can confirm the diagnosis and explore my options further.
Best of luck to you.