Punch Skin Biopsy in Diabetic Neuropathy

Measurement of unmyelinated C and A delta nociceptors through punch skin biopsy has been an important development in diabetic peripheral neuropathy over the past decade. The technique provides an objective pathological window into a population of fibers that is invisible to standard electrophysiological techniques and as a result has been difficult to investigate. Clinically, the punch biopsy technique is most often used to define a length-dependent peripheral neuropathy, but can also be used to follow patients longitudinally over time. Epidermal nerve fibers are often lost early in diabetes or impaired glucose tolerance and can be the only objective measure of neuropathy in these patients. The accessibility of cutaneous nerve fibers has also given rise to several nerve injury paradigms from which regeneration can be efficiently measured. The chapter will review the skin biopsy technique and recent findings with respect to diabetes.