Poison ivy, poison oak, and poison sumac all contain urushiol, a toxic oil that triggers an allergic rash in most people 12 to 72 hours after contact. Urushiol can spread from contaminated clothing, ...

Exposure to poison ivy can result in a severe rash. While the rash may subside without treatment, home remedies, such as cold compresses or calamine, can help treat the rash and manage other symptoms.