pw1958, hi & welcome! Your post caught my attention, as I also had skin & various other problems for years. I'll do my "skin story" first...
I had years of recurrent annular (targetlike) nonscarrig, nondepigmenting lesions on upper arms & torso. I finally [duh!
] realized sun had to be the trigger, as time elapsed between sun & rash emergence kept shrinking. So I told my dermies (6 or more) this, my GP, my gastro, my urologist, ETC. In addition to the skin rashes, I also had severe GI problems, urinary misery, headaches, hair loss, joint pain, pain along long bones (shins & arms), weight loss, migraines, B-12 anemia, etc.
I had two deep-punch biopsies done locally, but STILL no answers. ("Rash of unknown etiology" one read.
) Finally I took myself to a *teaching hospital* rheumie who also sent me to a dermatopathologist (= dermie who does the pathology---the labwork---himself). BINGO! I learned that special "immunofluorescent stain tests" light up in a way characteristic to lupus, IF the rash is truly a lupus rash. My rash was quickly Dx'ed as SCLE annular form (annular = targetlike, and SCLE = subacute cutaneous lupus erythematosus.)
For the record, there's a 2nd kind of SCLE rash called "psoriasiform", that looks somewhat like psoriasis but ISN'T. And there are OTHER lupus rashes as well: bullous (blistery), tumid, etc. i.e., we always read about discoid & malar, but there are MORE!
My "bloodwork story" was even more uncommon. The rheumie explained that people with "my" rash very often test positive for anti-Ro; however, about 1/3of this subgroup remain ANA-negative. BINGO again! My overall Dx was "Ro-lupus", that rare category Angel mentioned, that accounts for only 3-5% of systemic lupus.
Also, in his hardcover, Dr. Wallace writes about *other* skin problems lupus patients get more frequently than the general population. There's even something called "lupus urticaria" (urticaria = hives)---Dr. Daniel Wallace discusses it. (Most libraries have his hardcover.)
Your history of JRA also caught my eye. My childhood & adolescence were peppered with episodes of severe pain, with pneomonia, with high fevers & convulsions when I was given heavy antibiotics, etc. My current rheumie was the ONLY dr. who looked WAY back at my lifelong history. He also asked if I'd ever read the "alternative criteria" for lupus. FYI, those criteria are right here, as a sticky post at the top of the thread list.
Also, there are some drugs that trigger lupus. And there are other drugs that trigger a lesser form known as DILE = drug-induced lupus. I think some BP meds are known culprits. Dr. Wallace covers these subjects, too. (He covers a lot! Great and useful book!)
Bottom line? I'm obviously merely a DUMB PATIENT, so please take what I write in this light. If your dermie & rheumie can't figure it out, maybe they can help you find a "super-specialist", like a dermatopathologist or a teaching hospital dermie or rheumie, who CAN? You must be terribly frustrated, but keep at it, OK? Post more when you have time. Meanwhile, sending you my best wishes, sympathetically, Vee