A vesicant is something which is capable of raising skin blisters on contact. Vesicants were notoriously used during the First World War as a chemical warfare agent, with armies utilizing compounds such as mustard gas to disable each other. Some vesicants are classified as chemical agents solely, with no known utility. Others may be useful in chemical manufacturing, and some medications can actually act as vesicants. It is important to avoid contact with vesicants whenever possible because they are highly corrosive and they can be extremely dangerous.
When human skin is exposed to a vesicant, a rapid chemical reaction occurs, triggering the formation of a water blister. The blister can be quite large, and often several blisters cluster together. Exposure is also usually very painful as a result of the damage to the skin The blisters will linger for several days, eventually resolving and subsiding, assuming that the patient does not experience further injury as a result of the chemical exposure. The skin may be scarred or irritated, and it is possible for infection to set in if the patient is not well cared for and kept in a clean environment.
Sometimes, people inhale vesicants. This can cause serious damage to the trachea and lungs, as the same reaction which occurs on the surface of the skin can occur inside the body as well. The patient may develop difficulty breathing, and often coughs heavily as a result of inhalation. Consuming blister agents can cause damage to the gastrointestinal tract, characterized by diarrhea and vomiting. Prolonged exposure or exposure to a highly efficient vesicant can result in death.
In the case of medications, most vesicants are chemotherapy agents. Chemotherapy is used in the treatment of cancer, and involves aggressively attacking cells to prevent a cancer from spreading and to encourage it to shrink. These drugs are tightly controlled because they are highly toxic. Sometimes, a situation known as extravasation occurs, in which chemotherapy drugs leak out of an intravenous needle and into the surrounding skin, causing a vesicant reaction as the drugs interact with the skin.
Care for someone who has been exposed to a vesicant varies, depending on the vesicant and the setting. People exposed to vesicants used in hospital and clinical settings usually get prompt attention because the exposure is quickly noticed and can be addressed by a doctor or nurse. People exposed to blistering chemicals in settings such as chemical plants should follow the emergency exposure protocol and seek medical attention immediately.