Contact with the poison ivy, oak, or sumac plants causes a rash (allergic contact dermatitis). The rash is caused by contact with the oil (urushiol) in these plants. Urushiol is an allergen, so the rash is actually an allergic reaction to the oil in these plants.
You may be more or less sensitive to the plants than other people. A more sensitive person will have a more severe reaction and will react after minimal contact with the oil.
The degree of sensitivity to poison ivy, oak, or sumac is affected by:
Last Revised: August 30, 2011
To learn more visit Healthwise.org
© 1995-2012 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.