How To Tell the Difference Between Poison Sumac, Poison Ivy, and Poison Oak (Updated 2023)

It’s been a great summer season, but there are still more weekends and warm evenings ahead of us with outdoor activities, hiking, and camping. Rashes caused by poison ivy, poison oak, and poison sumac are a type of allergic contact dermatitis and can leave your skin feeling very itchy and irritated. Here’s how to tell the difference between poison sumac, poison ivy, and poison oak and what to do if you get a rash from one of these plants.

The argument can be made that all greenery found in the woods looks about the same – and we wouldn’t disagree with you. However, some species are especially dangerous and can irritate your skin. Poison ivy, oak, and sumac all have one thing in common: an oil found in the plants called urushiol. Learn the differences between the three plants and what you can do to avoid contact and a resulting rash.

Poison Ivy: Common throughout the US, with the exception of Alaska, Hawaii, and parts of the West coast. Poison ivy can grow on a vine or a shrub and is characterized by three spoon-shaped glossy leaves, with smooth or tooth-like edges. The leaves change colors depending on the season: red in spring, green in the summer, and yellow/orange in the fall. Remember the age-old saying, “Leaves of three, let it be!”

Poison Oak: Poison oak is more common in Western US, and can appear in the Eastern US. Oddly, it is rarely found in the Midwest region. Poison oak usually has three leaf, but sometimes up to 7 per leaf group. It grows as a shrub or a vine. These leaves have deep tooth-like edges around each leaf.

Poison Sumac: This plant is often found in wooded, swampy areas, like the Southeastern and Northern US. Poison sumac has 7 to 13 leaves per stem, and it grows as a shrub or a small tree. Leaves are pointed and have smooth edges.

Here are a few extra facts to keep in mind should you encounter poison ivy, oak or sumac:

• If this is your first contact with urushiol, you may not see a rash at all
• A rash can appear after a few hours, a few days, or even up to a week after exposure
• Poison ivy and other poison rashes can’t be spread from person to person
• It is possible to pick up the rash from plant oil that may have stuck to clothing, pets, garden tools, and other items that have come in contact with these plants. The plant oil lingers on virtually any surface until it is washed off with water
• Even if blisters break, the fluid in the blisters is not plant oil and cannot further spread the rash

Tips for Prevention

• Remember the difference between the three leaves and keep an eye out when spending time outdoors
• Wash your garden tools and gloves regularly. If you think you may be working around poison ivy, wear long sleeves, long pants tucked into boots, and gloves
• Wash your pets if they have brushed up against poison ivy, oak, or sumac. Use pet shampoo and water while wearing rubber gloves. Most pets are not sensitive to poison ivy, but the oil can stick to their fur and cause a reaction in someone who pets them
• Wash your skin in cool water as soon as possible if you come in contact with a poisonous plant. The sooner you cleanse the skin, the greater the chance you can remove the plant oil

Tips for Treatment

Do not scratch the blisters. Bacteria from under your fingernails can cause infection.

You can relieve the itch by:

• using wet compresses or soaking in cool water
• using topical steroids or oral corticosteroids; prescribed by your physician

Notify a Medical Professional

• If you have a temperature
• If there is pus, soft yellow scabs, or tenderness on the rash
• If the itching gets worse or keeps you up at night

Our experienced team at Dermatology Associates of Rochester is here to help you through all your skin concerns. To discuss rashes and skin conditions with a knowledgeable provider, use our online form to request a consultation or call us at (585) 272-0700.