Poison ivy can cause a rash even in the winter or early spring, when few or no tell-tale leaves are visible.
Poison ivy leaves and stems contain oil, called urishiol, which can cause a red itchy rash or blisters several days after you touch it. This oil can be transferred from clothing, tools, and pets to your skin. The best protection is to avoid contact with poison ivy or to wear protective clothing.
Wash anything that may have come in contact with poison ivy before the oil touches your skin.