What Causes Numbness In Fingers On Left Hand With History Of Sjogren S Syndrome?

I am a Sjogren s patient and possibly Lupus - they are not sure. Being treated for Lupus as they are so similar. I have lost the feeling in my pinky and ring finger on left hand. I now believe this is due to the Lymph node. What doctor can diagnose this issue? I have a Rheumy, but he does not seem too interested.