Lewisite (chlorovinyldichloroar-sine) is an arsenical vesicant that is a colorless to brown liquid with a fruity to geranium-like odour. Lewisite is more volatile than mustards and is soluble in organic solvents.
The initial clinical effect of Lewisite is erythema followed by blister formation within seconds to minutes of exposure. Pain occurs early, but is generally not severe. Damage caused by Lewisite to the eyes, airways and skin heals relatively quickly, and patients rarely develop secondary infections. For these reasons, and because the scavenger, British anti-Lewisite (dimercaprol) is an effective antidote, Lewisite is of secondary importance today as an agent of chemical warfare.