Poison ivy, oak and sumac rashes are all caused by the same resinous oil. This oil produced by the plants is called urushiol (pronounced oo-roo-she-all). The rash is your body's allergic reaction to the oil. This results in an itchy, bumpy rash that can produce blisters filled with fluid. A common misconception is that breaking the blisters will cause the fluid to spread the rash. If your poison ivy, oak or sumac rash is spreading, it is because the rash-causing oil is spreading.
An important step to ending your poison plant rash misery is to remove the urushiol oil from your skin. To remove poison ivy from your skin, wash with Tecnu Original Outdoor Skin Cleanser. This will unlock the bond of the oil allowing your skin to begin its natural healing process. Since everyone's immune system is different, a rash may last anywhere from a few days to several weeks. It depends on how long it takes your body to heal.