Summer is finally here. It’s time to get outside and enjoy the beautiful New England weather. But before you do, take some time to think about a few common hazards that could be lurking in your own backyard: poisonous plants. About 85 percent of people in the United States are allergic to poison ivy, oak and sumac. It is the most common allergic reaction in the U.S., affecting about 50 million people a year. Read on to learn how to identify poison ivy, oak and sumac and five facts to help you prevent and treat reactions.
Plant Identification

Poison ivy typically has three shiny green leaves budding out of a small reddish stem, attached to a hairy ropelike vine. The leaves grow to 2-5 inches long and often have pointy tips and ridged edges. The middle leaf is usually on a longer stem than the other two. Poison ivy is found in all regions of the contiguous United States.

Similar to poison ivy, poison oak typically grows in leaf groups of three but can sometimes have up to seven. The leaves resemble oak leaves with toothlike edges and can grow on either a vine or a shrub. Poison oak is most common in the Western U.S. but can appear in the Eastern U.S., as well.

Poison sumac grows 7-13 leaves per stem that are pointed with smooth edges and surfaces, typically arranged in pairs. The plant usually grows in moist, wooded areas of the Southeastern and Northern U.S.
Here are five facts to know if you come into contact with one of these poisonous plants:
- The rash is not contagious, but the oil is easily spread.
Poison ivy, oak and sumac release an oil called urushiol that can cause a rash (a.k.a. dermatitis) when it comes in contact with skin. The rash usually appears 12-48 hours after exposure to the oil. Touching the plant is one way to be exposed. You can also be exposed indirectly by touching items with urushiol on them such as clothing, tools, or even pets. You may develop multiple rashes on different parts of your body. Contrary to common belief, the rash itself is not contagious. The rash spreads by touching the oil and then touching another area of skin. That’s why it is important to wash your skin immediately after exposure. - Long clothes and washing are the most effective prevention methods.
Wear long sleeves/pants, socks and/or boots, and gloves to prevent exposure to poisonous plants. Any clothing that may have been exposed to one of these plants should be washed immediately with detergent and hot water to avoid spreading oil remnants. Barrier skin creams containing bentoquatam can also help protect your skin, although they are not as preventative as long clothing. - Avoid burning, mowing, or whacking at poisonous plants.
It is important not to burn poison ivy, oak, or sumac as inhaling the smoke can cause severe – and potentially life-threatening – respiratory irritation. It’s also dangerous to use a lawn mower or trimmer on poisonous plants as doing so breaks them up into small airborne particles that can land on you or someone else and cause multiple rashes. - Treat immediately.
If you think you’ve come in contact with poison ivy, oak or sumac, you may be able to prevent a reaction by immediately washing your skin with soap and water, rubbing alcohol, or a specially formulated cleanser for poison plants. It is important that you wash right away because your skin will absorb the oil quickly. Then rinse your skin thoroughly with cool water. To avoid spreading the oil, wear gloves while touching or washing anything that may have made contact with a poisonous plant. - Don’t scratch!
Avoid the temptation to scratch the rash as it could cause it to become infected. Scratching will not cause the rash to spread, however if the rash appears to be spreading you may still have oil on your skin or under your fingernails. Relieve the itch by using calamine or hydrocortisone cream, taking lukewarm baths, or applying a cool compress to the affected area. The rash should start improving after a week to 10 days. If not, the skin could be infected and may require treatment from a dermatologist.
All in all, don’t let poisonous plants ruin your outdoor fun. Allergic reactions caused by poison ivy, oak, or sumac can be extremely irritating and sometimes severe, so taking these simple precautions and knowing what to look for is a small and worthwhile tradeoff. Protect yourself, your friends, and family from poisonous plants for an itch-free and adventurous summer! And if you get a rash that concerns you, visit one of our ClearChoiceMD Urgent Care centers for help.