I’ll second the academic center referral. There are so many rare (& not so rare) diseases that most docs don’t want to or don’t know to test for. Theres also seronegative disease that makes treatment hard to get covered or creates liability most average docs don’t want to take on but the truth is most of these blood tests aren’t 100% accurate. Docs at an academic center will have more ability to test & work outside the box. The tests that finally illuminated my condition after years and years of watching and waiting and suffering, came through a Neuroimmunologist not a rheumatologist. I had; blood tests for all three antiphospholipid syndrome antibodies, a paraneoplastic panel blood test, a stem to stern mri, a lumbar puncture & the skin biopsy for small fiber neuropathy. I still struggle with dx confusion, causation, and getting treatment bc docs never seem to agree, but at least I have a few answers and docs willing to try something! I wouldn’t wait to long if you’re not at an academic center already. It’s really important to catch some conditions early. Trust yourself & your body!