Poison ivy, oak, and sumac contain an oil called urushiol which is readily absorbed through the skin and elicits dermatitis. Poison ivy, oak, and sumac are extremely common sources of dermatitis rashes that affect people from every age group; although, sensitivity can decrease with age. The reason for this is its ability to elicit an allergic reaction in the skin which is caused by the oily resin urushiol. Armstrong and Epstein state that it only takes 50 micrograms of urushiol to cause a reaction in most people. This is about the same amount as a grain of salt. Identifying Poison Ivy Poison ivy (Toxicodendron radicans) contains clusters of three distinct leaflets with the middle leaflet slightly longer than the other two. Typically these leaflets are 2-4 inches long. The leaflets are not connected at the same point on the plant but alternate at their connection point. Poison ivy usually forms as a vine but can also be found as a bush. In the spring the leaflets obtain a red coloration, turning to shiny green, and then yellow, red, or orange in the fall. Small green flowers grow in bunches at the stem near the leaflets. White drupes (drupes having only one seed while berries have …show more content…
Contrary to popular thought it is not actually secreted by the plant. This means that casual contact will not cause an allergic reaction unless the plant is damaged and the urushiol is exposed. Even small breakages of the plant can expose the urushiol contained within, so even though it doesn’t look crushed there may be an exposure hazard.Urushiol samples aged over 100 years have been known to elicit an allergic response and can easily penetrate the skin. Scratching and rubbing an area containing urushiol spreads the oil and expands the contamination. A simple test to determine if a plant contains urushiol is to crush a leaf between a sheet of white paper. The urushiol in the plant will darken due to oxidation after 10