Poison ivy is a type of plant that can cause a skin rash called allergic contact dermatitis when it touches your skin. The red, uncomfortable, and itchy rash often shows up in lines or streaks and is marked by fluid-filled bumps (blisters) or large raised areas (hives). The poison ivy plant contains a type of oil, called urushiol, that can trigger an allergic reaction when it comes in to direct or indirect contact with the skin. So even if you don't directly touch the plant, you can still be exposed if you touch something that has the oil on it, such as a pet's fur or gardening tools. Not everyone who touches the oil will develop poison ivy. You must be sensitized to the oil in order to be affected. Follow the links below to find WebMD's comprehensive coverage of poison ivy, including what it looks like, how to treat it, and much more.