[Confirmation of the use of skin biopsy in small-fiber neuropathy. First results].

INTRODUCTION: In small-fiber neuropathy, skin biopsy reveals a reduction of intraepidermal nerve fiber density (IENFD), a feature often necessary for diagnosis. In France, this technique has not been widely used for this purpose.

PATIENT AND METHOD: To validate this method, we studied 13 patients with suspected small-fiber neuropathy, analyzed their nervous intra- and subepidermal network with a punch skin biopsy and compared our data with those of literature.

RESULTS: Ten patients had pure small-fiber neuropathy and three an axonal polyneuropathy involving large-caliber nerve fibers. In the group of patients with pure small-fiber neuropathy, we found medium IENFD (11.6 +/- 4.46 fibers per millimeter in the proximal thigh and 7.15 +/- 3.59 fibers per millimeter in distal leg), well correlated with the electron microscopy quantitative and qualitative analysis of the unmyelinated subepidermal fibers.

CONCLUSION: This work demonstrated the good reproducibility of skin biopsy for analyzing the small-fibers in our cohort. These results require further confirmation in a larger cohort and validation in comparison with controls analyzed on a local level. Nevertheless, these techniques seem to be useful to assess the difficult diagnosis of small-fiber neuropathy.