Poison Ivy, Poison Oak, and Poison Sumac
Poison ivy, poison oak, and poison sumac are plants that frequently cause allergic skin reactions. How Poison Ivy, Poison Oak, and Poison Sumac Affect Skin These 3 plants contain sap oil (urushiol) in their leaves, stems, and roots, which is released on contact and penetrates the skin to cause an itchy, red rash (allergic contact dermatitis). Once urushiol is on the skin, it can be spread to other areas of skin by touch. People can also come into contact with urushiol by petting an animal that has sap oil on its fur. Rarely, urushiol can spread to other people through contact with clothing or objects (such as garden tools or fishing equipment) that has urushiol on it.Read more
