How is dermatitis caused?

There are two main kinds of dermatitis:

• Irritant contact dermatitis – caused by substances that physically damage the skin such as wet work, dyes, and shampoos.
• Allergic contact dermatitis – caused when your body's immune system becomes 'sensitised' to a particular substance, like the latex in some rubber gloves.

Certain air-borne chemicals, for example, in aerosols, can cause irritation to the skin, mouth and throat. Sensitisation can occur suddenly even when you have been working with a substance for years. After you have been sensitised you will have an allergic reaction to even tiny amounts of the substance, and may also become allergic to related substances.