Things we do in our life can also influence our health. Such as how much sun you took in, if you're around unfiltered flourescent lighting much, what you eat or drink (for some of us), etc. So it might be that something you did or didn't do over the last week or so. Stress can also influence a lupie, and for me, I have to admit, in a *big* way. For me, allergens are big also, since if the pollen count for certain things get up (or dust), and I react to that, my lungs swell, I go into an asthmatic reaction, and my lupus flairs, which is stressful, and starts the cycle... For a while there, I was keeping a "diary" of things I ate, did, etc. through the day (what a *bother* that was), in an attempt to figure out if I was eating/doing something to caused my varied flares. There wasn't any one or two things that stood out, so "it just happens" was decided. I call the doctor's office when I start having what feels like a flare, and they'll usually bump up my prednisone. My new rheumy is doing me on plaq now, and we hope to eliminate prednisone, and just use it when needed.
Have you seen some of the other posts, where folks talk about their dose of plaquenil? I'm a guy, 6'2" tall, and I'm on 400 a day, 2 in the morning, 2 in the evening. Other folks are smaller, and are on 200 a day. btw, I used to eat ibuprofen like candy. There's a little mention in the plaq hand-out that mentions being careful with certain otc meds. Not that there's any imminent danger involved with them, just that some folks have issues, especially in high dose (which I was doing). Of course, that applies for most any med. I can't find the paper right now (naturally)...
"There but for the grace of God, go I."
"... His mercy endureth for ever."