Two case reports: Electrothermal (aka contact) burns and the effects of current density, application time and skin resistance

Abstract

Electrical properties can be changed by the passage of current, where increased current/voltage reduces resistivity [3–8]. Electrical resistive heating is generated within the skin. Decreased skin resistance often correlates with increased skin permeability [3,9,10]. Results indicate that skin resistance depends strongly on V = voltage (V), J = current density (A/ cm), I = current (A) and A = electrical contact area (cm). Early studies show that high current densities occur in lowresistance pathways. This occurs only with dry or dirty electrodes, which make poor skin contact [10–12]. Several skin burn cases were reported because of poor electrode design [13] and poor electrode–skin contact [14,15]. Skin can be damaged by resistive heating due to the passage of current. A persistent temperature of 45 8C is generally accepted as the safety limit for skin burns [16]. Using the results of previous studies [13,17] the burn factor (BF) is defined as