blister agents/vesicants, chemicals that cause blistering of the skin or mucous membranes on contact. These agents include phosgene oxime, lewisite, distilled mustard, mustard gas, nitrogen mustard, sesqui mustard, and sulfur mustard. Exposure is mainly by inhalation or by contact with the skin or eyes. Inhalation causes shortness of breath, tachypnea, and hemoptysis, and death may result from the accumulation of fluid in the lungs; contact with the skin causes blistering and necrosis; and ocular contact causes swelling of the eyelids and corneal damage and can lead to blindness. Exposure to high doses affects the cardiovascular and nervous systems and may lead to cardiac arrest, convulsions, and coma. If these agents are ingested, nausea, vomiting, hematemesis, and diarrhea result. No antidote exists for most blister agents and treatment consists of removal of clothing, washing of the exposed areas, and supportive care. Lewisite can be neutralized by the application of British antilewisite if it is done soon after exposure.
