Pathology of Small Fiber Neuropathy: Skin Biopsy for the Analysis of Nociceptive Nerve Fibers

Reduced skin innervation as shown by immunostaining in skin biopsies is a sensitive and specific indicator of small fiber neuropathy (SFN). Standard methods for staining and quantification have been established, and normative values are available. However, not every condition with reduced skin innervation is a SFN, and not all types of disorders with pathological small fiber function manifest with reduced skin innervation. Identification of nociceptor subpopulations in humans in the skin is only beginning to yield data. Detection of inflammatory cells and pathologic deposits are additional diagnostic benefits of skin biopsy.