Allergic contact dermatitis is a form of dermatitis/eczema caused by an allergic reaction to a material, called an allergen, in contact with the skin. The allergen is harmless to people that are not allergic to it. Allergic contact dermatitis is also called contact allergy. Allergic contact dermatitis is common in the general population and in specific employment groups. It is more common in women than men, mainly due to nickel allergy and, recently, to acrylate allergy associated with nail cosmetics. Many young children are also allergic to nickel. Contact allergy to topical antibiotics is common in patients over the age of 70 years old. Allergic contact dermatitis is especially common in metal workers, hairdressers, beauticians, health care workers, cleaners, painters, and florists.