There are two types of contact dermatitis: allergic dermatitis, which is an allergic skin reaction, and irritant dermatitis, which develops after encountering an irritating substance over time, according to the American Academy of Dermatology (AAD). According to the National Eczema Association (NEA), the word “dermatitis” is used to describe any rash, but contact dermatitis differs from atopic dermatitis in that it develops as a result of something touching the skin versus being genetic. Contact dermatitis, a type of eczema, is a skin reaction that results when you come into contact with substances your body is sensitive to.