Poison Ivy: America’s Rash

"Leaves of three, let them be" is good advice, but you’ll need more than that to deal with problems caused by this toxic plant. Here's what you should know about poison ivy.

poison ivy

The mere sight of poison ivy just may get your skin crawling—or even itching.

© Lightscribe | Dreamstime.com

Unless you live in Alaska, Hawaii, a desert, or at a high altitude, poison ivy is creeping around nearby. If you don’t stay away from it, you may be one of the 50 million Americans affected each year.

Poison ivy, poison oak, and poison sumac all contain an oil called urushiol. It can cause an allergic reaction in the form of a blistering rash and an impossible-to-ignore itch. The poisonous plant presents three problems: recognizing it, treating it, and avoiding it.

What Does Poison Ivy Look Like?

Poison ivy’s basic summer appearance is a vine or shrub that has green, three-leaf, pointed clusters (“Leaves of three, let them be”). It can appear as ground cover, upright in bushes or shrubs, or as vines that grow up trees or rock walls. Several other plants (box elder, raspberries, blackberries) have a similar appearance.

Poison ivy’s color changes with the seasons:

  • In spring, the leaves emerge with a reddish color.
  • In summer, they’re green. The plant may also have clusters of light green or cream-colored berries.
  • In the fall, the leaves change to shades red, orange, or yellow.
  • In winter, its leaves disappear, but the leafless vines can still produce enough of the oil to cause a rash after contact.
poison ivy rash

If you’ve been hit hard by poison ivy, then you know the agony this type of serious rash can cause.

How Is Poison Ivy Treated?

Poison ivy is a year-round nuisance, but it’s especially toxic in spring and summer. A nick or quick brush against the plant is all it takes.

The classic symptoms of poison ivy—a red rash, blisters, and itching—can appear within a few hours of exposure or as long as 12 days afterwards. Without treatment, the symptoms go away in two to three weeks.

If you know you’ve come into contact with poison ivy, flush the skin with lukewarm, soapy water as soon as possible (every minute counts), says the American Academy of Dermatology. Then do it again. Don’t scratch, and don’t break the blisters when they appear.


For additional information, check out the post Homeopathy and Home Remedies for Poison Ivy, written by Becky Rupert, ND, CNC, CCH, for our friends at Countryside Network. Important point: “If you suspect that you have contacted poison ivy, the most important thing is to try to remove the oil as quickly as possible. Remove clothing and shoes within 10 minutes and throw them in the washing machine in hot water.”

Oral antihistamines can relieve itching, as can wet compresses and short baths in warm or cool water. Over-the-counter topical corticosteroid preparations might help, or you might try trade-name products such as Calamine Lotion or Aveeno.

See a doctor or go to emergency room if:

  • You have a temperature over 100 degrees
  • The affected area develops pus or soft yellow scabs
  • The rash spreads to your eyes, mouth, or genital area
  • You have trouble breathing
  • Home remedies don’t ease the symptoms

A Bit of Good News

There is some good news regarding a mostly-bad-news situation. The rash you get from poison ivy is not contagious and does not spread. It might appear to be spreading, but it’s because of a delayed reaction to urushiol in the areas of skin affected.

poison ivy warning sign

Take precautions in your clothing if you’re outdoors—long sleeves, as well as long pants tucked into your boots. And heed warnings like this one.

How Can You Prevent Poison Ivy Exposure?

If you’re going to be working near poison ivy, wear long sleeves and pants tucked into garden boots. Use gloves that don’t allow fluids, including oils, to pass through. It’s a good idea to wash any item of clothing that has been in contact with poison ivy, and regularly wash garden tools.

If you have a dog who may have brushed against a poisonous plant, use pet shampoo to wash the dog. Pets aren’t sensitive to the oil, but if it gets on their fur and you touch it, you’ll have a reaction.

Also, don’t put poison plant leaves in a campfire or when burning leaves in your yard. Urushiol can go airborne.

Stay Away

Poison ivy can be easily pulled out in early spring if only a few plants are involved. Pull out the entire root system, if possible, and put it in a plastic bag to be taken away.
When poison ivy has been in an area for a long time, it is almost impossible to remove the plant and its root system. The best way to protect yourself is to stay away from it.

As a service to our readers, University Health News offers a vast archive of free digital content. Please note the date published or last update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

Tags: , , , , ,

Jim Brown, PhD

As a former college professor of health education, Jim Brown brings a unique perspective to health and medical writing. He has authored 14 books on health, medicine, fitness, and sports. … Read More

View all posts by Jim Brown, PhD

Enter Your Login Credentials
This setting should only be used on your home or work computer.