Hypothermia as an Adjunct Therapy to Vesicant-induced Skin Injury

OBJECTIVE The notion that cooling vesicant-exposed tissue may ameliorate or prevent resultant injury is not a novel concept. During both World Wars, studies were conducted that investigated this potential mode of therapy with sulfur mustard and seemed to conclude that there might be merit in pursuing this research direction. However, it does not appear that these studies were followed up vigorously, and the literature that describes this work is not readily accessible. In this report, we compare the toxicities of lewisite and sulfur mustard in vitro and in vivo and also provide an overview of historical and recent work on the effect of temperature on the toxicity of these vesicating chemical warfare agents. METHODS Tissue culture and animal studies were utilized to examine the effects of hypothermia on vesicant-induced toxicity. RESULTS Cytotoxicity was either significantly delayed (lewisite) or prevented (sulfur mustard) when cultures were maintained at 25 degrees C. However, the effects of hypothermia on sulfur mustard-induced cell death were reversible when the cells were returned to 37 degrees C. Despite these in vitro results, animal studies demonstrated that the therapeutic cooling of both mustard sulfur-exposed and lewisite-exposed skin resulted in dramatic and permanent protection against injury. Cooling also increased the therapeutic window in which drugs were effective against vesicant agents in tissue culture and lewisite-induced skin injury. CONCLUSIONS The simple and noninvasive application of cooling measures may not only provide significant therapeutic relief to vesicant-exposed skin but also increase the therapeutic window in which medical countermeasures against vesicant agents are useful.