What an excellent question you have asked about!
With tremendous disappointment, the three diseases mimick each other very well, which makes it "almost" impossible to know which one is flaring. I have a horrible time - especially lately - knowing which one is being the bad guy. I have all three.
Here's how I figure out what's going on....
1) I increase my Prednisone. If I feel better, it is lupus or sjogrens. If I feel worse, it is fibro. ( fibro is NOT inflammatory, so any prednisone or anti-inflammatory medication doesn't work. It actually makes the symptoms worse).
2) Go get blood work/urine tests done. IF everything comes back normal, it is a fibro flare. There are NO blood tests to determine fibro activity. Everything will look normal. CBC, ESR, liver enzymes, urine. Will all be normal. If there is an increase in my ESR, it's lupus or sjogrens.
3) Check my lymph nodes. If I have swollen glands at the base of my skull at the back of my neck, swollen glands in my armpits, along jaw line, groin area, I have a sjogren's flare. Although, it can indicate a lupus flare too. But for me, I don't usually get swollen glands with my lupus. It's different for everyone.
Most of the time, just by increasing or decreasing my prednisone, I can get a very fast indicator of what's going on. It's much harder to determine the difference between a sjogren's and lupus flare. If you notice your mouth, eyes, nose, vagina being much more dry then usual, then it's the sjogren's acting up.
I'm sure there will be others with more information for you too. this is a great thread you posted Hester. So many of us, even us veterans of the diseases have a lot of trouble knowing what to do and what not to do! It's really hard! Getting to know our bodies well will help in the long run.
Have a good day!
I can do anything through Jesus Christ who strengthens me. I have learned in whatever state I am in,to be content. Phillipians 4:11-13
34 years old. Diagnosed with lupus in 2000. Fibromyalgia, anti-phospholipid syndrome(APS)(stroke),Sjogren's, Raynaud's, seizure disorder-(miraclulously disappeared!), Libman Sach's Endocarditis, vasculitis, sacroiliitis, arthritis (neck) . Prednisone, Imuran, Coumadin, Clobazam, Amitriptyline, didrocal, Cozaar, Tramacet, calcium, Cykolokapron, multi-vitamin, vitamin D, Magnesium, vitamin B6, Acidophilus