What is the role of skin biopsy for evaluating small fiber neuropathy in patients with rheumatic disease who have treatment recalcitrant pain?

I have a shared decision-making discussion with the patient, especially alluding to the fact that the result would not change my therapy (i.e., use neuropathic analgesics for treatment) for small fiber neuropathy (SFN).

Where I find it especially useful is in a patient with systemic lupus (SLE) or Sjogren's disease (or other SFN-associated disorders) who was led to believe that their symptoms are not significant (or even are not "real") because their nerve conduction velocity testing was WNL.

O...

This is a great topic for discussion, and I want to thank all experts who made very valuable comments.

As a Neurologist, I tend to side more towards Dr. @Dr. First Last’s opinion. What I would encourage everybody to read is a review article by 3 international experts in SFN (Drs. Lauria, Faber and Cornblath) published in 2022 which explains what skin biopsy is and what an abnormal result means. To put it simply, skin biopsy is just another TEST and an abnormal result is just another abnormal numb...

There are a lot of aspects to this question. But they all fall under the umbrella of: "What will the biopsy tell me that will change treatment decisions or change diagnostic thinking?"

I rarely order skin biopsy for IENFD as the symptoms are usually pain, and the treatment for this pain will not be influenced by the biopsy results.

With regards to having a confounder such as RA, one would like to know what the odds of having abnormal IENFD in RA is without neuropathic symptoms. That answer is not ...

I greatly appreciate the thoughtful perspectives shared by Drs. @Dr. First Last and @Dr. First Last on the nuances of interpreting skin biopsy results. While I agree that small fiber neuropathy (SFN) is ultimately a clinical diagnosis that should not rest solely on a single abnormal ENFD number, I believe dismissing the utility of ENFD testing—particularly in rheumatologic practice—risks overlooking its significant diagnostic, prognostic, and therapeutic implications.

ENFD Testing Is Not Intended...