urushiol

Urushiol is an oily chemical found in plants like poison ivy, poison oak, and poison sumac. When you come into contact with these plants, urushiol can trigger an allergic reaction characterized by itching, redness, swelling, and blisters. This occurs because the immune system mistakenly identifies urushiol as a threat and reacts violently. The oil can bind to skin and other surfaces, so even indirect contact or touching contaminated objects can cause a reaction. The best way to prevent a reaction is to avoid contact with these plants and wash skin thoroughly if exposure occurs.