Meds for hyperthyroidism can cause a rash - if the rash was there beforehand, then the Graves (I presume this is the cause of the hyperthyroidism) can cause itching/rash due to autoimmune processes.
The joint pain may be thyroid - also thigh muscle weakness is common in hyperthyroidism, making knee pain even worse. If rheumatoid arthritis has been tested for (the blood tests pick up 80-90% of cases), then it may be reasonable to see if the pain improves with treating the thyroid before doing more tests.
Hello. I have Graves and I am pretty new to all this too. At the beginning of my medication I was so itchy on my arms - I was unconsciously scratching all day wherever I was (a few people asked me if I was ok?). I'm not really itchy anymore though.
(Wait a sec - I have to go back and read the rest of your blurb -I've forgotten)
Oh yeah, I find it interesting that you saw a rhuematologist as a year before I was diagnosed I have muscle pains in my legs (I felt like I had been running a marathon and they ached all day).I had ANA (Anti-nuclear antibodies) and saw a rhue.. too.Although it all came to nothing and now I have a hyperactive thyroid.
I really can't give any advice, but to do a heap of searches on the net and you might find something out. Or maybe one of the smart people who answer my questions around here may help out. i just wanted to let you know that I too have those symptoms.