Tecnu Extreme is a medicated poison ivy scrub that works in 15 seconds to treat symptoms as well as remove the urushiol oils that cause painful, itching rash. The scrub can be used to both stop the rash from spreading once it starts and also prevent the rash from starting at all. Tecnu Extreme is designed specifically for individuals who have a chronic problem with poison ivy, oak and sumac.Tec Laboratories, Inc., Albany, OR.