There are many types of chemical-warfare agents that affect different parts of the body. Blistering agents affect the skin and include
Blistering agents, which cause the skin to blister, can also damage the lungs and airways. Mustards can also affect the ability of the bone marrow to produce white blood cells that fight infection and sometimes cause cancer of the skin or airways long-term.
Some agents have characteristic odors. For example, sulfur mustard has been variously described as smelling like mustard, garlic, horseradish, or asphalt. Lewisite may have a geranium-like odor, and phosgene oxime has been described simply as irritating. However, the perceptions of these odors are so subjective that they are not reliable indicators of the presence or identity of these compounds.
Mustard compounds cause intense skin pain and redness. A few hours after exposure (sometimes as long as 36 hours later), blisters form. Blisters caused by sulfur mustard sometimes resemble a string of pearls around a central area that appears to be unaffected but is actually too damaged to blister. Blisters caused by nitrogen mustard are less likely to show this pattern. Blisters may become large and full of fluid. The eyes may be painfully inflamed, and the corneas may become cloudy. People cough and have hoarseness, wheezing, gasping, and windpipe spasms. They may feel tightness in their chest and be short of breath. Nausea may develop.
Lewisite causes pain within a minute or so of skin exposure. Skin redness is often noticeable within 15 to 30 minutes, and blisters develop after several hours. The blisters usually form at the center of the reddened area and spread outward. Pain begins to subside after the blisters form. Irritation of airways occurs soon after inhalation and leads to coughing, sneezing, wheezing, and shortness of breath from fluid leaking from small blood vessels into the alveoli (tiny air sacs in the lungs). After a few hours, people may feel tightness in their chest and be short of breath.
Skin contact with phosgene oxime causes intense, stinging ("nettling") pain and whitening within 5 to 20 seconds. The affected skin then turns gray with a red border. Within 30 minutes of exposure, pale, slightly elevated swellings called wheals (similar to those in hives) develop. During the next 7 days, the skin becomes dark brown and then black as the skin and underlying tissues die. If not surgically removed, wheals may persist for more than 6 months.
Pain occurring at or shortly after exposure suggests to first responders that Lewisite or phosgene oxime is the chemical agent involved. Delayed onset of pain (sometimes a day after exposure) suggests exposure to sulfur mustard. Tests available only in special laboratories can confirm the diagnosis.
People exposed to mustard compounds should have regular blood tests for two weeks to monitor for a decrease in their white blood cell count that can be caused by these agents.
First responders quickly try to decontaminate peoples' eyes and skin. They use a specially formulated commercial topical skin-decontamination product (called Reactive Skin Decontamination Lotion, or RSDL®). Soap and water may smear sulfur mustard rather than remove it, but they can still be used when there are no other options for the rapid decontamination of mass casualties. High-flow low-pressure water (for example, from a garden hose) alone can also be used to decontaminate the eyes and skin.
Doctors treat blisters as if they were regular burns from heat or fire, give the person fluid by vein, and cover the burns with sterile dressings. Scrupulous hygiene is important to prevent infection. Antibiotic ointment is applied to the edges of the eyelids to prevent the lids from sticking together.
Supplemental oxygen is needed for people who have trouble breathing. Nausea can be treated with drugs such as atropine.
The views expressed in this article are those of the author and do not reflect the official policy of the Department of Army, Department of Defense, or the U.S. Government.