By Julie Wiekamp, MPAS, PA-C
Everyone remembers a bad case of poison ivy. The itchy rash is not easily forgotten. Yet, the plant is hard to spot and there are many misconceptions on how it is spread. Allergic rashes caused by plants are usually a result of poison ivy, poison oak, and poison sumac. All of these plants contain the oil urushiol. Urushiol is found in stems, leaves, roots and fruit. Approximately 50% of individuals will break out in a rash after coming into contact with the oil in nature. No skin type is immune to the oil- all ethnicities are affected.
Poison ivy and oak’s leaves are arranged in a group of three that arise from a single stem, thus the phrase, “Leaves of three, let them be.” The plants produce an off-white fruit in the autumn. Poison sumac is different from poison ivy in that the leaves are often seen in groups of 5 or more. Plant removal is often difficult. Burning the plants is not recommended since inhaling the oil may cause irritation to the lungs. The oil will not penetrate heavy vinyl gloves, although it will penetrate through rubber or latex gloves.
Those who work or play outside are at a higher risk for running into the plants. If you have accidentally made contact with urushiol containing plants, it is best to gently wash the skin as soon as possible. It is, of course, best to wash the oil off within 10 minutes of exposure. However, washing your skin even 1-2 hours after exposure provides some benefit. You can be exposed to the plant oil by touching clothing or fur that has come into direct contact with the plant. Therefore, if you suspect you have been around poison ivy, it is best to wash all clothes, shoes and camping items. Remember to wash your pet as well! The rash is not spread by the blister fluid. You must come into contact with the oil itself in order to get the rash.
A poison ivy rash is often reddened and itchy. It is usually readily identified in clinic- although sometimes it may mimic other types of rash. Over the counter treatments such as calamine lotion and oatmeal baths are helpful to calm and soothe the itch. More moderate to severe rashes require prescription steroids to help stop the allergic response. On occasion, scratching will bring about bacterial infection. Watch carefully for signs of secondary infection to include redness, swelling, crusting and drainage.
Identification of the plant is key to prevention. For further help in identifying the plant see the links below: