Recognizing Poison Ivy, Oak and Sumac
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Health Tip of the WeekPublished on
Health Tip of the Week The old saying goes: "Leaves of three, let them be." Poison ivy, oak and sumac are three plants that carry the same poison — urushiol, a colorless, odorless oil that causes an itchy, irritating rash in almost everyone who comes in contact with it.
Poison ivy (A) usually has three broad, tear-shaped leaves. It can grow as a climbing or low-spreading vine that sprawls through grass. It is found everywhere in the United States except Alaska and Hawaii. It often grows along rivers, lake fronts and ocean beaches.
Poison oak (B) has leaves that look like oak leaves and grows as a vine or a shrub. The plant can have three or more leaflets per group. It is most common in the western United States.
Poison sumac (C) has seven to 13 leaflets per stem that are characterized by smooth surfaces and pointed tips. It is most often found in wooded, moist areas of the southern United States.
You can develop a rash by touching poison ivy, oak or sumac, or by touching something that recently came into contact with the oil, like clothing or a pet.
The body's allergic response to the plant toxins may not appear for several days, and severity can change from person to person. The skin will become red and swollen, and then blisters will appear.
After a few days, the blisters will become crusty and start to flake off. They can take one to two weeks to heal.
The rash itself is very itchy and uncomfortable, but it is not contagious. You can’t get the rash by touching the skin of an affected person as long as they have washed off the oil.
After contact with poison ivy, oak or sumac, immediately wash the exposed areas thoroughly with soap and cold water. A bath may spread oil to other parts of your body; showering or hosing off outside is the best way to remove the oil.
It is also very important to wash all clothes and shoes immediately after exposure because oils can remain on them and cause reinfection.
If a rash develops, you can try to relieve itching by:
Call your doctor if the rash spreads to the eyes, mouth or genitals. Seek immediate medical attention for severe reactions, especially those resulting in swollen eyes or face or difficulty swallowing or breathing. An oral or intravenous steroid, such as prednisone, and possibly additional medication, such as epinephrine, may be needed to treat severe allergic reactions.
Most allergic reactions will clear up in 14 to 21 days. However, if the symptoms persist or worsen, contact a doctor for further treatment.
Visit the Poison Control Center’s website to learn more about poison ivy, oak and sumac, as well as other plants that can irritate the skin. If you have any prevention or treatment questions, call us at (800) 222-1222. The Poision Control Hotline is available 24/7.
Contributed by: Jeanette D. Trella, PharmD, BCPPS
Categories: Weekly Health Tips, Poisonous Plants
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