Contact dermatitis occurs when the skin comes in contact with an irritant that causes an allergic reaction.

There are two main types of contact dermatitis:

1. Irritant contact dermatitis accounts for 80% of all contact dermatitis and happens when the skin is exposed to irritating substances, such as solvents, detergents, soaps, bleach or nickel-containing jewelry. Makeup, hair dye, nickel-containing scissors, belt buckles or clothes with metal snaps or zippers can also trigger reactions — as can over-washing hands with hot water and soap or wearing scratchy wool.
2. Allergic contact dermatitis is a delayed allergic reaction that appears as a rash a day or two after skin is exposed to an allergen. Common examples are poison ivy, nail polish and poison oak. Fragrances, nickel and the preservative thimerosal, which is found in some topical antibiotics, are also common causes of allergic contact dermatitis.

Disclaimer

This is to be only used as an educational piece and individuals should not use it to self-diagnose a skin condition or problem.