How to verify Sjogren's diagnosis?

Hello ... I was fortunate enough for my fingers to actually change colour while at my rheumatologist appointment.
They all went (on both hands) a dusty plum color .. my toes often do that too. The doctors were fascinated to actually see in real time one of the symptoms of Raynaud's ... they warned me to watch for discoloration and if it became more intense and painful ... go to ER.
So far it hasn't gotten that bad.
If your friend has symptoms like that ... keep track of when and how often ... stress can bring it on, which is what I think happened to me.
I hope she finds answers.

I had a biopsy by an Ent. He took four glands sent them off to be tested.
Second, test was done by my eye doctor. He put some kind of strips of paper in my eyes. Normal is 5 or above. I had less than 1% of fluid in my eyes. Then he looked at my cornea and it was all scratched up.

It is a clinical diagnosis. A good rheumatologist or ent can make after ruling out other causes.

The rheumatologist should do a blood test for anti-SSA (anti-Ro) or anti-SSB (anti-La) These are specific for Sjögren’s and was how I was diagnosed.

I will pass this info along to my friend. A blood test will be simple and non-invasive. Thank you very much.

That won’t be enough to completely identify you are positive. I had a positive ANA and was elevated on both those labs. The doctor ordered Connective Tissue disease test, also elevated.
This doctor was in Boston and said to have a definitive positive for the autoimmune disease I needed the lip biopsy. I went the easy root. I then when to the eye doctor and failed that. I probably am positive but I suffer numerous drug confirmed allergies so I didn’t want to try any new drugs. I read a lot and I’m doing well on my own. Best of luck.

@gardeningjunkie, If your friend hasn't already seen the Sjogren's Foundation website, it has quite a bit of information on diagnosing the condition - https://sjogrens.org/understanding-sjogrens/diagnosis.