I have Mixed Connective Tissue Disease which is closely related to Lupus. I cannot recommend highly enough the blog "coolinginflammation" - in fact, Dr. Ayers' information is what led me to radically change my diet. It's all about controlling, you guessed it, inflammation.
My most important dietary rules are no grains and no vegetable oils, followed closely by no sugar.
My last flare-up before changing my WOE was almost 2 months long, with extreme exhaustion (12 hours of sleep, still needing a nap, contemplating pulling my car over during my commute to sleep, etc.), joint pain throughout, mental fog, extreme Raynaud's, increased alopecia, etc. I changed my diet just a couple months later and my next flare up lasted only about 2 weeks and, I would say, was only 40% strength of the previous one. Of course, it was still life disrupting and very upsetting (I think I was overly confident about my diet COMPLETELY managing my disease), but much much more manageable.
I'm on daily medication (plaquenil) and my goal is to eventually not have to take it anymore. But for now, I am allowing my body to slowly recover from the poisons that are grains, and following conventional medical advice. Of note, not one of my doctors ever mentioned changing my diet because I'm slender, my HR is good, my cholesterol is good and I ate "healthy" (low-fat, high grains, low protein).
I had an uncle with Lupus and he lived well into his late 80s; I don't feel fatalistic about auto-immune diseases. I physically and mentally feel the best I have in my entire adult life and now I hope I live to 90 or 100. The only thing that saddens me is that based on the recommended American diet, I essentially lost so much of my life feeling like I was in a machine that was slowly breaking down.
Because if you didn't know, of that is life made: only of moments; Don't lose the now.