This warning is very important if you’re camping or hiking because poison ivy is often found growing on the forest floor. Poison ivy is a low-growing shrub, but it can also grow like a vine. Vines can growlaterally from a single shoot or bud, making it appear that the plant is growing in a straight line.
Did you know? Poison ivy is a woody perennial, it’s scientific name is Toxicodendron radican.
We call this plant "poison ivy" because if it comes in contact with your skin you will develop a very itchy red rash. This rash can start small, but will spread and can even produce blisters — an allergic reaction to a toxic oil found on the plant, called urushoil.
Did you know? The medical name for a poison ivy rash is "urushiol-induced contact dermatitis".
Once urushoil gets on your skin, it binds to receptor proteins located on the surface of specialized skin cells called Langerhan’s cells. These Langerhan’s cells then interact with specialized cells of the immune system, called T-cells. The job of T-cells is to protect your body from suspicious or foreign substances like urushoil, as well as bacteria and viruses. These immune cells respond aggressively by releasing enzymes to destroy the foreign substance and any nearby cells. During this immune response,your skin turns red because extra blood is sent to that part of your skin (a process called vasodilation) and it becomes itchy because the immune cells also destroy nearby nerve endings.
Only humans are sensitive to urushoil. Animals are not harmed by urushoil and they will not develop a rash if they touch poison ivy because they don’t have the same immune response as humans. In fact, many animals, such as deer, goats, horses, and even birds, will eat the leaves of poison ivy. You, on the other hand, definitely don't want to eat poison ivy, since it will result in lots of unpleasant symptoms!
Did you know? The best way to remove urushoil from your skin is with alcohol.
The good news is that a poison ivy rash is easily treatable and only last a few weeks.
Article first published March 14, 2011.