Objective:To study the mechanism of epithelium polarized change of skin on electrical injury and burn and provide an objective and quantitative index on them.Methods:Specimens including 380V alternating current(AC)

220V AC

220V direct current(DC)

flame burn

hot metal burn and the control group are dyed with hematoxylion-eosin

immunohistochemically examined with antibody against EGFR

and observed with transmission electron microscopy

respectively.Circumference

long axis

short axis and long /short axis ratio of the polarized epithelia nuclei were also measured by computerized image analysis and calculated.Results:There are homogeneous on ultrastructure among injured groups.Immunohistochemical staining with EGFR showed positive and uniform staining in injured and normal skin.Epithelia Nuclei of skin on all injured groups are elongated.By measuring the circumference and the long/short axis ratio of epithelia

there were no significant differences among three electrically injured groups(P>0.05).The same conclusion was also obtained between the flame burned group and hot metal burned group(P>0.05).But there were obvious differences between each electrically injured groups and each burned groups(P<0.05).Conclusion:Epithelium polarized change of skin on electrical injury and burned skin is mainly resulted from thermal effect.The circumference and the long/short axis ratio of polarized epithelia nuclei of injured skin may be used to differentiate lowvoltage electrical injury from burn.