I want to share my recent revelation. I have been dealing with what was thought to be RA for a few years. Multiple locations for arthralgias, but never the fingers or toes. Serum negative. I responded well to prednisone, but nothing else, and went through five different biologics, along with methotrexate and leflunomide. Recently, I was diagnosed with pericarditis, suffering pitting edema in both legs. Finally, I went to Mayo Clinic for more robust testing and examination. First day, resident RA doc interviews me for an hour and goes over records. Senior RA doc comes in and says that it does not fit. Symptoms are wrong for RA. On top of xrays, blood and cardio MRI, he orders a synovial fluid draw and wants it tested. I tested positive for Whipples disease, a bacterial infection. Extremely rare diagnosis. Whipples can attack just about anything in your body. It is most commonly diagnosed as a digestive disorder, but even there, it has been misdiagnosed as Celiac or Irritable Bowel Syndrome. A biopsy is required, taken during an upper endoscopy. Now, synovial fluid can be tested. I believe that it should become a common test for unusual RA cases, serum negative. And particularly with cardiac or digestive issues added on. Unfortunately it is mostly unknown. The benefit of Whipples is that it is relatively easy to treat. A month of IV anitbiotics, then a couple of years of oral antibiotics and you're probably cured. Without proper treatment, it will kill you sooner than RA. And the immunosuppressants are working against you with Whipples. You will need your immune system.