Re: Hi, new to this board quick question.....
Hi & welcome. I *think* (I'm just a patient, obviously) that between Lyme and lupus, SYMPTOMS may be overlap some but test results vary substantially. Also, Lyme is caused by a spirochete, while in lupus an aberrant immune system produces antibodies to one's own cell matter.
The diagnostic criteria & tests differ. In systemic lupus, drs. look for four or more of the ACR criteria, per the "sticky post" at the top of the Board.
The disease-specific rashes are also different, I think. You could try to find pics of lupus rashes, e.g., malar, subacute cutaneous annular form, subacute cutaneous papulosquamous form, discoid, tumid, bullous, etc. And the skin TESTS also differ, I *think*. A lupus band skin test looks for 5 or 4 (or 3, etc.) of specific immune reactants---IgG, IgM, IgA, C3 and fibrinogen. The more that show, the greater the odds that it's lupus; and the visible band is a continuous line. Dr. Daniel Wallace's lupus hardcover discusses this briefly.
But because this stuff is only properly understood by experts, maybe you can just ask your dr(s). to share their thinking in plain English? You could ask for copies of your labwork, including the attached "detail pages" of your skin tests, meaning not just the top sheet which often says very little.
Oh---I was Dx'ed with the subacute cutaneous subset of lupus (SCLE) after decades of varied problems. My annular arm/torso nonscarring rashes were the last problem to arrive: I had these rashes for 8 years, about 4x yearly. Had many dermie appts., multiple punch biopsies, endless bloodwork, and no answers. Why? My suburban drs. were looking for "classic" SLE & seemingly had never heard of the SCLE subset, first differentiated in 1978 or so. Translation: suburban docs were at least 20 years out-of-date. In contrast, the teaching hospital rheumie & dermatopathologist I saw both roared into action & I got the Dx in less than a month.
Hope this helps! Post back if anything catches your eye, OK? Best wishes & GOOD LUCK! Sincerely, Vee