First Time User? Sign Up Now
First Time User? Enroll now.
Home > Health Library > Contact dermatitis
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.
Current as of: October 31, 2019
Author: Healthwise Staff
Medical Review:Adam Husney MD - Family Medicine & Martin J. Gabica MD - Family Medicine & Amy McMichael MD - Dermatology
To learn more about Healthwise, visit Healthwise.org.
© 1995-2020 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.