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:
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 substance.
|Primary Medical Reviewer||Adam Husney, MD - Family Medicine|
|Specialist Medical Reviewer||Amy McMichael, MD - Dermatology|
|Current as of||March 12, 2014|
WebMD Medical Reference from Healthwise