Recent reports of ISIS using chemical weapons have been emerging from multiple sources. The main chemical threats mentioned are “mustard agents”.
The use of chemicals or biological agents in war in not new. The first use of these types of agents was in April 1915 by the Germans who used sulfur mustard in Ypres, Belgium. These agents are typically classified into one of three broad groups and go by the acronym NBC for nuclear, biological and chemical.
Here I will briefly look at chemical agents and specifically mustard and lewsite type agents after a basic review of all three types.
This is simply the deliberate spread of radioactive materials that are harmful to humans and animals. There are multiple methods to spread this radioactive material from simply placing radioactive material in a public space to using explosive devices to scatter the material. While there are multiple types of radiations including light, sound, radio waves, microwaves and heat, the chief concern here will be ionizing radiation.
This is the the use of biological agents, chiefly bacteria, viruses and some naturally derived poisons to harm humans and animals. Anthrax, Plague, Smallpox, Viral Hemorrhagic Fevers and Ricin are classic examples of these agents.
Chemical agents are broadly divided into several categories based on their mechanism of action within the body. Nerve agents, Blister or Vesicant agents, Blood agents and pulmonary intoxicants are the traditional groups and division. Examples of well know nerve agents include sarin and VX chemicals. Blister agents include mustard and lewsite while blood agents are cyanide. Pulmonary agents include chlorine and ammonia.
Sulfur Mustard is spread either by vapor inhalation or direct contact with the liquid. Damage to the skin, eyes, airways and internal organs is common. Skin blisters and respiratory distress are most common manifestations. There is no specific treatment or antidote.
Mustard is an oily yellowish/brown liquid that generally smells like garlic or mustard. At temperatures above 100F it is a vapor hazard. Due to its oily consistency, cross contamination is a concern.
Mechanism of Action:
Mustard is absorbed and causes cell damage in 1-2 minutes after contact although clincal effects can take hours to emerge. Hours after exposure the patients will usually begin to present for medical care. There are no immediate clinical symptoms. The most common interval between exposure and symptom onset is 4-8 hours.
Eyes are typically effected as a conjunctivitis and is dose dependent. Worse exposures produce worse symptoms. Redness and watering are typical.
Skin effects begin hours after exposure and erythema, burn and itch are common. Vesicles form and then coalesce into larger blisters.
Pulmonary effects are due to damage of the mucosa and airways. Upper airways are effected first and spread downward into the bronchioles depending on dose and exposure time. Pulmonary edema is rare but can occur.
Blood forming system effects are longer term concerns and require a significant exposure. The White Blood Cell count begins to decrease due to damage to precursor cells in the bone marrow. Lack of these cells increase susceptibility to infections.
Treatment of Mustard Type Exposure:
There is no specific treatment or antidote. Decontamination of the patient is paramount to prevent further damage from the agent. Irrigation with saline or water is important as is taking care to avoid cross-contamination. Supportive care with creams and pain control is also important management.
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