Contact Dermatitis
What is the second way in which Contact Dermatitis can develop?
The second way is by sensitization. This means that the first contact with the substance causes no immediate trouble. But the exposure "sensitizes" or changes the sensitivity of the skin. Then, afterward, whenever the skin is exposed to the same substance — even slightly — it becomes inflamed. This is called an "allergic contact dermatitis". And a perfect example of it is poison ivy dermatitis.
Another uncommon but interesting mechanism in the development of contact dermatitis is what is called "photo-allergy". This means that some chemicals contained in perfumes, soaps or medications may "sensitize" the skin to sun rays. Afterward, when the person is exposed to sunlight, a rash develops.
The types of skin reaction caused by sensitization are the same as those caused by irritants.
This article also includes: