Urushiol is a chemical found in the oil of mango sap. Urushiol is also found in poison ivy and poison oak. Therefore, people who have a history of reactions to poison ivy and poison oak should be cautious when handling mangoes. Contact with urushiol causes an itchy, blistering skin rash in some people, called allergic contact dermatitis. Touching mango tree leaves, bark, or the skin of mango fruit can lead to itching, red skin, hives, and blisters that typically begin 1-2 days after exposure. People who are sensitive to contact with urushiol can usually eat mango fruit without problems, because the pulp of the mango fruit does not contain urushiol.