What you need to know about poison ivy

What you need to know about poison ivy

“Leaves of three, let it be.”

This familiar rhyme has long been used as a reminder to watch out for poison ivy. But urushiol, the substance found in the plant’s sap that causes a rash, is also present in poison oak and poison sumac. The three plants have different appearances and are commonly found throughout the country. They can cause the same irritating rash known as allergic contact dermatitis.

Dr. Madhuri Dave, an emergency medicine physician with Advocate Children’s Hospital, shares advice for prevention and treatment.

“Poison ivy grows as a bush or vine and has three leaves together,” she explains. “Whereas poison oak grows as a vine or shrub and also has three leaves on each leaflet. Although, these leaves appear more rounded than poison ivy. Poison sumac leaves are clustered and grow as a tree.”

She says while many people worry about these plants specifically in the summer when they are spending more time outdoors, they pose a threat all year.

“You can develop a rash from contact with urushiol any time of year,” she says. “Protect yourself by avoiding the plants and wearing long pants and sleeves when outdoors. Change your clothing when you’re back home.”

Many people will develop a rash within hours of contact with urushiol, but for others, it may be days before an itchy rash, redness and/or blisters appear.

“A common misconception is that the rash is contagious,” Dr. Dave says. “The rash and/or blisters do not contain urushiol. But if you touch a person, pet, or gardening, hiking, or camping tool that has come in contact with urushiol, you can develop a rash from that. You will also only notice a rash on your body in places that have come in contact with urushiol. The rash does not spread.”

Most rashes will resolve on their own in a few weeks. There are over-the-counter treatment methods available to help relieve pain and itching, including anti-itch creams and antihistamines. Other at-home remedies may also help, such as wet compresses.

If you or your child has been in contact with a poisonous plant and develop a fever, have trouble breathing, or if the rash worsens over time, contact your physician for help with appropriate treatment.

Are you trying to find a doctor? Find one in Illinois or Wisconsin. 

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Comments

4 Comments

  1. Thalia Jenkins July 24, 2024 at 11:07 am · Reply

    What do poison ivory looks like up close

  2. If you have or suspect poison ivy, a simple remedy is to use (Before blistering) a wash-cloth with soap and warm water and scrub the infected area with the same effort or pressure you would use to remove stubborn engine grease. (Be sure to launder the wash-cloth after.)

  3. I discovered my iPhone can sometimes identify plants in pictures I’ve taken, including poison ivy. View your picture of an unknown plant, then swipe up.

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About the Author

Holly Brenza
Holly Brenza

Holly Brenza, health enews contributor, is a public affairs coordinator on the content team at Advocate Health Care and Aurora Health Care. She is a graduate of the University of Illinois at Chicago. In her free time, Holly enjoys reading, watching the White Sox and Blackhawks, playing with her dog, Bear and running her cats' Instagram account, @strangefurthings.