My understanding of this from the recent medical seminars I attended is that Fibro is a central pain disorder.

It can be triggered by anything that sets up a pain sequence.
Listed were
Trauma --like a car accident.
Arthritis
PN
Infections
Vaccines

We were told that trigger point diagnosis is no longer valid. And that Fibro was basically like having a radio on full blast with no volume control. Eventually small signals from the periphery get magnified in the brain and read as a higher pain level than really exists.

Also that it runs in families, and that an 8 fold occurance is possible if family members have it.

So yes, PN and Fibro can exist together. The PN would be the trigger for the Fibro.

Research is still ongoing about it.