It has for many years been subject of controversy whether the presence of Demodex mites in follicles is a cause of disease or just a normal finding. Some doctors--yours is apparently one of them--try treating the mites in hopes of getting clinical improvement. That's reasonable, since such treatment is safe and the worst that can happen is that it doesn't work. If it doesn't, a trial of rosacea treatment might be worth considering (despite the biopsy report.) Lupus does not seem worth considering as a possibility, since that condition has a pretty definitive pathologic picture that you don't have.
It my be that you just have sensitive skin that blushes and flushes and feels sensitive. In that case, all you can do is do the best you can to avoid things that stimulate flushing, and use products that agree with you. These maneuvers are never wholly successful, but they do help. Often, it takes trial-and-error to determine which products re best, since almost all the ones you can buy re tested to be safe for the majority of people.
Best.
Dr. Rockoff