Skin biopsy for peripheral neuropathy

Estimates of intraepidermal nerve fiber densities (IENFDs) obtained from 3 mm punch biopsies of skin have emerged as a method to diagnose small fiber sensory polyneuropathy, e.g., chronic idiopathic axonal polyneuropathy. The technique is reported to be diagnostically useful, especially in patients with normal nerve conduction studies. However, earlier investigations of Meissner corpuscles found variable densities of contiguous biopsy sites, especially in older persons, a limitation of the technique for diagnostic purposes.¹

With visualization of unmyelinated nerve fibers using immunoreactivity to protein gene product 9.5 protein, it became possible to count these fibers in skin punch biopsy specimens. There are reports on its validity, tolerability, and reliability.^2-5 An alternative to punch biopsy is skin blister biopsy using suction, the latter separating epidermis from dermis.⁶ William R. Kennedy, who with colleagues developed the blister technique, gives two reasons for preferring blister to punch: 1) less scarring and 2) possibility of sampling a larger area (W.R. Kennedy, University of Minnesota, personal communication, 2008).

In this issue of Neurology®, Panoutsopoulou et …