I receive IVIG for PN/SFN and have had improvement. But I will warn you that IVIG is extremely expensive and typically insurance requires other treatments (steroids, anti-seizure, anti-depressants, etc) be tried first before you'll get a chance at IVIG. That being said, if you have a positive skin biopsy, documented autoimmune disease, and/or a doctor willing to go to bat for you, then you might get a trial without all the red tape.

You are correct in that it treats the root of the problem and can actually increase fiber density (and this can be confirmed with follow-up skin biopsies).

Can't hurt to try to get IVIG from the start...just don't be surprised if you have to try other treatments first.