Plaquenil may help with the fatigue and sometimes joint pain related to autoimmune disease, but not nerve pain. There is some research that indicates it can slow progression of some autoimmune processes, but it's hard to prove or track this when so little is known about the progression of AI diseases to begin with. Keep in mind that it take a good 6 months or so to start working. Make sure to get a base line ophthalmologist evaluation before starting the Plaquenil and then EVERY 6-12 months after that.

I'm glad you are getting some relief with the Cymbalta.

The skin biopsy can be repeated down the road if your continue to get worse...and maybe the borderline level will have changed...allowing you to qualify for IVIG or another treatment.