Shingles without a rash, zoster sine herpete

Hi,
I am hoping that someone can provide me with concrete and the most current information regarding diagnosing shingles in the absence of a rash.  I have a history of left-sided rib, shoulder, and back pain along with ocular inflammation in my left eye.  In the process of working up my issues, three separate doctors (internist, rheum, ophthalmologist) have suggested (independently) zoster sine herpete as a possibility.  I have had a VZV test (ELISA), HSV1, HSV2, IgG, and IgM tests.  The only one that was positive was the VZV test.  I had chickenpox as a child.  Is there a better or more specific test, or tissue to study, in order to rule this in or out?
Thanks for any help you can provide.