poison ivy rash

Poison Ivy Rash: Symptoms, Treatment, and Prevention   What Is Poison Ivy? Poison ivy is a plant that contains an oily resin called urushiol. When urushiol comes into contact with the skin, it can trigger an allergic contact dermatitis, causing redness, itching, swelling, and blisters. The rash usually develops 12 to 48 hours after exposure […]