Changes in skin structure and electrical properties following high voltage exposure.

Abstract

Human skin experiences extensive alterations when exposed to a strong electric field. In high voltage electric shocks, tissues in the current path undergo large-scale changes; the stratum corneum (SC), the outermost layer of the skin, loses its barrier function against ionic transport. The primary mechanism of electric field interaction with the skin is the creation of aqueous pathways, which increase the permeability of the skin to ions and macromolecules. Changes in skin structure and electrical properties were characterized by measuring the transport of fluorescent molecules in an in vitro preparation of human cadaver skin in a permeation chamber. Application of high voltage pulses (Uskia > 150 V, tau pulse = 1 ms) decreased the skin resistance per unit area by three orders of magnitude from its initial value of 100 k omega-cm-2. The resistance reached a quasi-steady state after about 20 pulses. After the cessation of pulsing, Rskin recovered immediately to about 4 k omega-cm-2 and remained low for 2 h thereafter. Transport of fluorescent molecules by high voltage pulses occurs in highly localized transport regions (LTRs), with diameters not exceeding 100 microns for short pulses (tau pulse < 5 ms).