| Risk Factors Contact dermatitis is inflammation of the outer
layers of the skin caused by contact with a particular
substance. It usually presents as a rash that is typically
confined to the specific area of the body where the contact
occurred. Copyright © Nucleus Medical Media, Inc. Contact
dermatitis is usually caused by either an irritant or an
allergen. An irritant is a substance that irritates the skin. An
allergen is a substance that causes an allergic reaction. People
may be exposed to certain substances for years and never have a
problem, and then suddenly develop contact dermatitis. Some
common causes of contact dermatitis include: - Metals, such as
nickel (common in jewelry allergy) - Cosmetics and toiletries -
Plants, such as poison ivy A risk factor is something that
increases your chance of getting a disease or condition. Risk
factors include: - Contact with an irritant or allergen -
Allergies to certain substances, such as plants, chemicals, or
medications The symptoms of contact dermatitis ma