What is occupational irritant contact dermatitis?
Dermatitis is a localized inflammation of the skin. In general, inflammation refers to a condition in the body when it is trying to react to a localized injury of tissues. Signs of inflammation include some or all of the following: redness, heat, swelling, pain.
Occupational irritant contact dermatitis is an inflammation caused by substances found in the workplace that come in direct contact with the skin. Signs of irritant contact dermatitis include redness of the skin, blisters, scales or crusts. These symptoms do not necessarily occur at the same time or in all cases. This kind of dermatitis is caused by chemicals that are irritating (e.g., acids, bases, fat-dissolving solvents) to the skin and is localized to the area of contact.
Another kind of contact dermatitis, allergic contact dermatitis, is different because it is an allergic response to skin contact with some allergy-causing material (e.g., poison ivy). Another difference is that allergic dermatitis can occur in other places on the body that did not come in contact with the allergy-causing material.
How does irritant contact dermatitis develop?
In the workplace, irritant contact dermatitis can develop after a short, heavy exposure or a repeated or prolonged, low exposure to a substance. The appearance of irritant contact dermatitis varies considerably according to the conditions of exposure. For example, an accidental contact with a strong irritant causes immediate blisters. Contact with a mild irritant may only produce redness of the skin. However, if the irritation continues, small lesions or sores appear on the reddened area; afterwards crusts and scales form. The skin damage usually heals a few weeks after exposure ends if no complications have arisen (e.g., no infections occurred).
The irritant action of a substance depends on its ability to change some properties of the outer layer of the skin that acts as a protective barrier against toxic substances. Among other changes, some substances can remove skin oils and moisture from the outer layer of the skin. This reduces the protective action of the skin and increases the ability of irritants to enter or infiltrate the skin. The removal of fat or fat-like material from the skin is also responsible for the dryness, cracking and whitening of the skin.
To produce the damage, the irritant substance must infiltrate the outer layer of the skin. Following infiltration, the substance comes into contact with cells and tissues. The substance also reacts with certain chemicals naturally present (endogenous) in cells and tissues. These reactions produce skin damage. The body's first reaction to the damage is a localized acute inflammation. The cells and tissues try to repair the damage and set up a defensive response to remove the invading material causing the damage. During the body's defensive response phase, a person may experience pain, warmth, redness and swelling in the irritated area.
Minimal skin damage, as in the thickening of the inner layer of the skin, will not be visible. However, when the damage is severe, the skin shows signs of chapping, scaling, and blistering. Some skin cells also die. Typically, an irritant reaction develops within a few hours from exposure and is at its worst after approximately twenty-four hours.
What are factors contributing to irritant contact dermatitis?
Factors contributing to irritation include
the chemical properties of the substance (for example, is it an acid, an alkali, or a salt),
the amount and concentration of chemical coming in contact with the skin, and
the length and frequency of the exposure.
Factors peculiar to individual workers are also important. Hereditary factors influence the variety of reactions seen in different persons when exposed to the same irritant.
The part of the body that comes in contact with an irritant substance is another factor to remember. The penetration of substances varies over different body regions. For example, some substances penetrate the face and the upper back more quickly than the arms.
Environmental factors play a significant role. For example, hot, humid workplaces cause workers to sweat. Sweat can dissolve some types of industrial chemical powders that may come in contact with the skin. This increases their toxic or irritant effects of the chemicals because solutions penetrate the skin more readily than solids. On the other hand, sweating may also have a protective function because it may dilute or wash out substances. Working where the air humidity is low or where the skin is wet for prolonged and repeated periods can cause chapping of the skin that, in turn, can increase the possibility of irritation.
Friction against the skin, occurring while operating grinding machines and other equipment can scrape away the skin, reducing its protective action against irritants. Clothing soaked with irritants is another important factor. Cuts or skin injuries enable irritant substances to penetrate the skin more readily. Table 1 summarizes some factors that contribute to skin irritation.
Dermatitis is a localized inflammation of the skin. In general, inflammation refers to a condition in the body when it is trying to react to a localized injury of tissues. Signs of inflammation include some or all of the following: redness, heat, swelling, pain.
Occupational irritant contact dermatitis is an inflammation caused by substances found in the workplace that come in direct contact with the skin. Signs of irritant contact dermatitis include redness of the skin, blisters, scales or crusts. These symptoms do not necessarily occur at the same time or in all cases. This kind of dermatitis is caused by chemicals that are irritating (e.g., acids, bases, fat-dissolving solvents) to the skin and is localized to the area of contact.
Another kind of contact dermatitis, allergic contact dermatitis, is different because it is an allergic response to skin contact with some allergy-causing material (e.g., poison ivy). Another difference is that allergic dermatitis can occur in other places on the body that did not come in contact with the allergy-causing material.
How does irritant contact dermatitis develop?
In the workplace, irritant contact dermatitis can develop after a short, heavy exposure or a repeated or prolonged, low exposure to a substance. The appearance of irritant contact dermatitis varies considerably according to the conditions of exposure. For example, an accidental contact with a strong irritant causes immediate blisters. Contact with a mild irritant may only produce redness of the skin. However, if the irritation continues, small lesions or sores appear on the reddened area; afterwards crusts and scales form. The skin damage usually heals a few weeks after exposure ends if no complications have arisen (e.g., no infections occurred).
The irritant action of a substance depends on its ability to change some properties of the outer layer of the skin that acts as a protective barrier against toxic substances. Among other changes, some substances can remove skin oils and moisture from the outer layer of the skin. This reduces the protective action of the skin and increases the ability of irritants to enter or infiltrate the skin. The removal of fat or fat-like material from the skin is also responsible for the dryness, cracking and whitening of the skin.
To produce the damage, the irritant substance must infiltrate the outer layer of the skin. Following infiltration, the substance comes into contact with cells and tissues. The substance also reacts with certain chemicals naturally present (endogenous) in cells and tissues. These reactions produce skin damage. The body's first reaction to the damage is a localized acute inflammation. The cells and tissues try to repair the damage and set up a defensive response to remove the invading material causing the damage. During the body's defensive response phase, a person may experience pain, warmth, redness and swelling in the irritated area.
Minimal skin damage, as in the thickening of the inner layer of the skin, will not be visible. However, when the damage is severe, the skin shows signs of chapping, scaling, and blistering. Some skin cells also die. Typically, an irritant reaction develops within a few hours from exposure and is at its worst after approximately twenty-four hours.
What are factors contributing to irritant contact dermatitis?
Factors contributing to irritation include
the chemical properties of the substance (for example, is it an acid, an alkali, or a salt),
the amount and concentration of chemical coming in contact with the skin, and
the length and frequency of the exposure.
Factors peculiar to individual workers are also important. Hereditary factors influence the variety of reactions seen in different persons when exposed to the same irritant.
The part of the body that comes in contact with an irritant substance is another factor to remember. The penetration of substances varies over different body regions. For example, some substances penetrate the face and the upper back more quickly than the arms.
Environmental factors play a significant role. For example, hot, humid workplaces cause workers to sweat. Sweat can dissolve some types of industrial chemical powders that may come in contact with the skin. This increases their toxic or irritant effects of the chemicals because solutions penetrate the skin more readily than solids. On the other hand, sweating may also have a protective function because it may dilute or wash out substances. Working where the air humidity is low or where the skin is wet for prolonged and repeated periods can cause chapping of the skin that, in turn, can increase the possibility of irritation.
Friction against the skin, occurring while operating grinding machines and other equipment can scrape away the skin, reducing its protective action against irritants. Clothing soaked with irritants is another important factor. Cuts or skin injuries enable irritant substances to penetrate the skin more readily. Table 1 summarizes some factors that contribute to skin irritation.
source:www.ccohs.ca
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