Poison ivy is a common plant in South Carolina that can make people miserable for weeks. Naturalist Rudy Mancke said the vine can both grow on the ground and can climb trees, which it likes to do. The itch and rash poison ivy (and its cousins, poison oak and the rarer poison sumac) produces can last for two to four weeks, according to University of South Carolina allergist Dr. David Amrol. He says it sometimes can be tricky to detect the rash’s source, because it doesn’t show up for at least 12 hours, and sometimes four or five days.
Though thought of as a warm weather threat, Amrol said poison ivy can cause itching and misery year round, because even when its distinctive three leaves fall off in cold weather, the oil which causes the rash is still on the vine. One small consolation was offered by both men. Most people believe that anyone who touches poison ivy will break out in the itchy rash, but that’s not so. One must be allergic to the plant to break out, though most people are. Amrol said about 25-30 percent of people are not allergic to poison ivy and can handle it with no effects at all – but he doesn’t recommend it. Both men also warned those with the allergy to wash their dogs if they roam in the woods, because even if people aren’t around poison ivy, a dog can brush up against it and bring the misery-causing oil home to its masters on its coat.