SLE and Psoriasis are both autoimmune disorder, but the comparisons kind of stop there. You should be able to tell the difference between a psoriasis rash and discoid rash (lupus), Psoriasis is usually silver scaly patches which are usually flat, whereas lupus rashes are red, raised and usually in areas that are exposed to sunlight (face, neck, arms, scalp) The patchees are different for every person, some people find them itchy, some find them painful, it really depends on the location and sensitivity of your skin. You need to find a rheumatologist, who specializes in Lupus, or a dermatologist that specialized in Discoid Lupus. They need to take a biopsy of one of the leisons, as well was these blood tests: ANA, dsDNA, CBC, sed rate& c-reactive protein, liver panel, Rheumatoid factor, Anti-SSA and Anti-SSB, and porphyrin. Now, don't hesitate to force you doctor to get these labs DONE. Since lupus is such a complicated disease to diagnose, you wan tto make sure all your bases are covered.( especially if your not seeing a specialist in lupus) Also, plaquenil, tends to not show many side effects. So even if you don't feel it's making a difference it doesn't mean its not working. Also most medications take up to 3 months to kick in, especially plaquenil. For either disease, plaquenil will help prevent further damage, even if it doesnt fix anything right away, it's great for preventative care. Also avoid methotoxate for as long as you can, there are plenty of other options before you jump to hardcore immuno-suppressants. You might also find trying Prednisone, it is a steroid, which has its own set of side effects but it can cause temporary relief. Really try and find a doctor who knows their stuff, most doctors know the basics of lupus, and they'll just throw you aside and hope you get better cause they have no idea what going on. Do you own research. Check out Lupus.org, I think they have a list physicians. Both psoriasis and lupus are serious conditions, so don't let things get worse. Good Luck!