When touched, almost every part of these plants has the potential to result in contact dermatitis, a severe, agonizing, and painful skin irritation. Urushiol can cling to items that have come into contact with the plants, such as clothing, shoes, tools, dirt, or animals, and subsequently poison an unwary victim. This is even more horrible. After hiking through places where these plants are present, take care to remove your clothing so that the outside does not come into contact with your skin. Wash your clothing as soon as possible. Even though the rash may last for one to three weeks, it usually does not require medical attention. The tips of the leaves and young stems of this herbaceous plant are covered in stinging hairs that contain formic acid and other irritants. When touched, these needle-like hairs inject stinging acid into the skin, causing a burning, tingling, and itchy rash. Fortunately, the signs and symptoms rarely persist for more than a day. Interesting to note is that the cooked plant can be eaten safely and is regularly eaten as a vegetable. Contact with sunlight can cause phytophotodermatitis, a condition where the skin develops painful blisters. Blindness may occur if the sap enters the eyes. It’s best to avoid most tall, carrot-shaped plants with white flower clusters since they resemble hogweeds and the deadly poisonous water hemlocks (Cicuta species).
