A vesicant (topical chemical agent which interacts with human tissues) mostly useful in chemical warfare, developed near the end of World War I by the Americans but never implemented at the war.
The various symptoms associated with exposure to Lewisite range in severity and time of appearance during the course of exposure.
- Ocular exposures cause eye pain and inflammation.
- Skin exposures cause immediate pain and symptoms similar to second and third degree burns. Lewisite diffuses more rapidly into skin than does mustard gas. Reddening of the skin generally appears within 30 minutes of exposure, following by blistering withing 4 to 24 hours. Relative to mustard gas, healing occurs more rapidly and the risk of secondary infection is less likely.
Based on material from http://www.mitretek.org/mission/envene/chemical/chem_back.html