Lewisite ocular injuries

Despite the twentyfold to thirtyfold increase in the toxicity of lewisite compared to the mustards, the ocular injuries caused by vapor exposure to lewisite are predicted to be less significant than HD under field conditions (Gates et al., 1946). Ocular irritation is almost immediate even at low concentrations, such that exposed personnel would be alerted to the presence of an irritant and able to rapidly take protective action. Second, the rapid onset of blepharospasm, ocular pain, and edema at low concentrations causes the eyes to close involimtarily, reducing the total ocular exposure. 

The vesicant properties of lewisite result from direct contact with the skin. Signs of dermal toxicity (pain, inflammation) may be experienced within a minute after exposure. Acute lethality is usually the result of pulmonary injury. Ocular exposure may result in corneal necrosis. Due to its lipophilicity, percutaneous absorption of lewisite is rapid and, at a sufficient exposure, may be associated with systemic toxicity characterized by pulmonary edema, diarrhea, agitation, weakness, hypothermia, and hypotension (lOM, 1993). The threshold for severe systemic toxicity in humans following dermal exposure to lewisite has been estimated at lOmg/kg (9.1-13.4 mg/kg) (Sollman, 1957). 

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