Skip to Main Content

A 40-year-old Kurdish émigré presents to your office accompanied by his daughter who translates for him. As a teenager, his village was gassed by the Iraqi military. He developed diffuse skin erythema over most of his body, profound eye pain and photophobia, and blepharospasm. No blisters developed, but within several hours he noticed mild upper airway irritation and a dry cough. He did not have any shortness of breath. Within a few days, he noticed his skin became dark and some areas desquamated. In the following six months he had recurrent respiratory and skin infections, but he has been otherwise well for the past twenty-four years. His exam is significant for patchy areas of hyperpigmentation.

There are two major classes of vesicants: the mustards and the arsenicals. Each class is discussed using a prototypical agent. A third agent, often classified with the vesicants, is phosgene oxime. This compound is poorly understood, but a brief discussion is warranted and can be found at the end of this chapter. Vesicants are more “strategic” in so far as they tend to injure rather than kill (compared to other classes of chemical weapons.) They cause injury by blistering whatever part of the body is exposed—internal or external. They may be released via bombs or aerosolized through sprays.


Mustards were identified in the early to mid-1800s, while arsenicals were developed in the United States during WWI. Although first used in 1917, three years into WWI and three years after the military use of chlorine gas began, mustards resulted in more WWI casualties than all the other chemical weapons combined—accounting for upward of 80% of all chemical agent causalities. Vesicants have been used since WWI, most notably by Iraq during the 1980s. The Iran–Iraq war inflicted an estimated 50,000 casualties, mostly against Kurdish Iraqis in northern Iraq. At present, no antidote exists for mustard gas. This is unfortunate as nearly a dozen countries maintain mustard as part of their cadre of chemical agents. In contrast to their use as chemical weapons, members of this class have found use as chemotherapy for certain types of cancers.


Mustards, including the nitrogen and sulfur types, are thought to be named for the pungent odor or from the yellow-brown color. They are among the most persistent of the chemical agents. Historically and militarily, sulfur mustards have played a bigger role and are felt to be more of a threat as a weapon of terror. Nitrogen mustards are considered battlefield agents and so are less likely to be encountered by the public (Fig. 24–1), but are discussed briefly as well.

Figure 24–1

Gas shells exploding on WWI frontlines.

Courtesy of the World War I Document Archive.

The chemical structure of mustard results in a highly reactive sulfur moiety, which ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.