Skin toxicity induced by wet heat

Pieces of human skin from the skin bank were heated in an autoclave for 1 or 5min at temperatures 80, 90, 100, 110 and 135°C. The pieces were then homogenized and the homogenates were injected intraperitoneally into groups of mice. The amount injected was either a quantity equivalent to 50 or 75% of the mouse body surface area. Fourteen separate experiments were carried out, each one with a variety of temperatures. Mortality in the groups of mice was recorded by the 8th day. Control mice received homogenates of skin heated to no more that 38°C and out of a total of 104 control mice there were only 4 deaths. In contrast homogenates of skin heated to 135°C killed from 80 to 100% of the mice in different groups, averaging 92%. Skin heated to 110°C killed from 33 to 90% of the mice in different groups, averaging 63%. Skin heated to 100°C killed from 0 to 80% of the mice in different groups, averaging 33%. Temperatures of 80 and 90°C killed no more than 10% of the mice in any group, averaging less than 3%. One minute of heating seemed to be sufficient to induce the toxic effect in the skin. These findings indicated that wet heat application to skin was capable of inducing toxicity in a fashion similar to that demonstrated many years ago with hotter dry temperatures applied to skin for 15s. That application was shown to induce polymerization of skin cell membrane lipid proteins rendering them toxic. In this study, increasing toxicity appeared similarly to depend on the quantity of wet heat input as illustrated by the range of increasing temperatures. The relatively lower temperatures of scalding versus flame burns can accomplish similar dangerous effects; it is simply a quantitative matter of heat input.