Poison Ivy | Causes & Risk Factors


How does poison ivy cause a rash?

The poison ivy plant contains an oil called urushiol (say: “oo-roo-shee-ohl”). This oil "bonds" to skin when it comes in contact with it. Most people are allergic to it. If you are allergic to urushiol and you get it on your skin, you'll develop an itchy, red rash. You can get the oil on your skin by:

  • Touching the poison ivy plant
  • Touching any clothing, including shoes, that have come in contact with the plant.
  • Touching any gardening tools that may have the oil on it.
  • Touching any pets that have been around poison ivy and have gotten the oil on their hair.
  • Burning the poison ivy plant. The oil from the plant is carried in the smoke.

Written by familydoctor.org editorial staff

Reviewed/Updated: 04/14
Created: 06/05