Rash from poison ivy. Many people develop an itchy rash that causes lines or streaks that look like this.
Many people get a rash from poison ivy, poison oak, and poison sumac. This rash is caused by an oil found in the plants. This oil is called urushiol (you-ROO-shee-all). The itchy, blistering rash often does not start until 12 to 72 hours after you come into contact with the oil.
The rash is not contagious and does not spread. It might seem to spread, but this is a delayed reaction.
Most people see the rash go away in a few weeks. To make the skin feel more comfortable during this time, you’ll find tips from dermatologists here:
If you have a serious reaction, you need to see a doctor right away. Swelling is a sign of a serious reaction — especially swelling that makes an eye swell shut or your face to swell.
You should see a doctor if the rash covers a large part of your body, you have large blisters, or cannot sleep.If you have trouble breathing or swallowing, go to an emergency room immediately.
Learn more about poison ivy:
Image used with permission of the American Academy of Dermatology National Library of Dermatologic Teaching Slides.