Unexplained Knee Pain That My Doctors Cant Figure Out?

I'm 18 years old, and I am having sever pain in both knees. I have Lupus and Rheumatoid Arthritis. I have taken Prednisone,Methotrexate,Plaquinil, Arava,and Naproxen..AND NOTHING IS HELPING! I have had x-rays and MRI's and both have came back normal.I cant stand no longer than 15 minutes without being in horrible pain. Whenever I stand my knees, ankles, and feet swell. My feet also turn bloody red and feel like they are on fire. When this happens my knees are always warm to the touch and my blood pressure rises. This has been going on for a year now and it's affecting my life greatly. I went to a Orthopedic and he basically said nothing is wrong with me in his eyes, that left me walking out of his office in tears because I know something is. My Rheumatologist doesn't know what to do with me anymore, he is wanting to send me to St Louis. But I'm wandering what could they do different. I am seeking any advice that might hep me.