Symptoms and Signs of Contact Dermatitis

Medical Author:
Medically Reviewed on 3/11/2019

Doctor's Notes on Contact Dermatitis

Contact dermatitis is a localized rash/irritation of the skin caused by direct contact with the substance to which the patient’s immune system reacts (allergic type) or by a skin irritant (irritant type). However, signs and symptoms can appear to be visually identical. Signs and symptoms of allergic contact dermatitis usually is a red rash that does not appear for one or two days on the skin after exposure (direct contact with the compound) while irritant type occurs more rapidly. The longer time of exposure to the compound, the more severe the skin reaction. The skin may itch and burn; contact dermatitis usually has more pain than other types of dermatitis and contact dermatitis frequently involves the hands.

Contact dermatitis (allergic type) is caused by a cellular immune response to small, simple molecules (for example, nickel metal in rings or watch bands). Immune cells produce chemicals that cause itches. Plants such as poison ivy, poison oak and poison sumac contain an oil or latex that triggers the dermatitis. Other compounds can include medicines applied to the skin and various cosmetic chemicals.

Contact dermatitis (irritant type) is caused by skin coming in contact with reception that is toxic to your skin. This is not an allergic reaction, it is a toxic reaction. Many chemicals can cause contact dermatitis; frequently encountered chemicals are those in household cleaners like detergents and industrial products such as solvents (for example, turpentine, xylene).


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.