Contact Dermatitis
How does Contact Dermatitis develop?
There are two ways.
The first is by means of irritation — chemical or mechanical. This is called an irritant contact dermatitis. An example of a chemical irritant dermatitis is one caused by the detergents or cleansing compounds mentioned previously. An example of mechanical irritant dermatitis is one caused by prickly fiberglass particles, or the scratchiness of wool clothing next to the body. If the irritant is strong — for instance, an accidental spill of lye on your hands — a single exposure will cause a violent inflammatory reaction. The skin will become itchy, red, swollen, and often develop tiny water blisters, called "vesicles", or even large blisters.
If the irritant is weak, the initial skin reaction will be mild. Only after repeated exposures — such as repeated exposure to soaps and detergents — will the accumulated damage to the skin be easily seen. When the dermatitis develops slowly in this manner, the skin shows dull red, itchy, thickened patches, at times accompanied by blistering. If the inflammation is located on areas where the skin bends, such as the fingers, painful cracks may develop, just as cardboard cracks when it is bent.
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