Contact dermatitis is inflammation of the skin caused by contact
with a substance that causes an allergic reaction. A minor case of contact
dermatitis may cause mild redness of the skin or a rash of small red bumps,
while a more severe reaction may cause swelling, redness, and larger blisters.
A rash usually starts about 48 hours after exposure to the
irritating substance. Common causes of contact dermatitis include:
Poisonous plants, such as poison ivy, oak, or
Soaps, detergents, shampoos, perfumes, cosmetics, or
Jewelry or fabrics.
New tools, toys,
appliances, or other objects.
The location of the rash may provide a clue about the cause.
Contact dermatitis does not usually occur with the first exposure
to the irritating substance (allergen). After a reaction to the substance
occurs for the first time, a rash can occur in response to even very small amounts of the
How this information was developed to help you make better health decisions.