I was reading this with interest because 10 years ago I was prescribed Plaquenil because of parasthesia.

I have never tested positive for Sjogren's (SSA & SSB antibodies), but I had mildly dry mouth and eyes that seemed to be sudden in onset. The weird parasthesias in face, hands and feet started soon after. I had a very mildly positive sed rate and ANA (50/50, if I recall correctly) and a positive antiphospholipid antibody test.
The rheumatologist looking after me at the time said it was possible to have the disease without all the bloodwork lining up.

My mom had the CREST variant of scleroderma, and my maternal grandmother had RA. I think my rheumy back then was pretty confident that I had Sjogren's related vasculitis, and plaquenil was the lesser of the evils for treatment. I took 200mg/2x daily. I took myself off Plaquenil recently since every round of bloodwork since has been negative, even for ANA. My mouth and eyes actually feel fine, but my neuropathy is getting worse. My current rheumy ordered a huge panel of tests when my neuropathy became worse this year--everything negative. It has been about 4 wks now without the Plaq. I figured why not try going without it to see if there is an improvement in neuropathy. I think I am going to just conduct these experiments on myself, lol.

I can keep you posted on this.