I experience a LOT Of tingling and numbness. My entire arm or leg will go numb at times, even if i'm not sitting in a weird position. There's really nothing I do, except that weird laugh-giggle through the pain thing that goes along with the pins and needles. I have fibromyalgia though, and i'm told it's rather common to have the tingling/numbness with Fibro. Not sure about Lupus though...sorry I couldn't be of more help!
Edit: it might be some sort of circulation problem, or problem with blood pressure. Perhaps mention it to your doc, couldn't hurt to ask!
One day at a time, one breath at a time... We can get through this.