One of the worst poison ivy problems can arise from severe allergic reactions to the plant. Not only the ivy, but also poison oak and sumac cause the skin to react to the sap they contain, called urushiol. The contact rash, which develops causes itching, and can develop immediately or days after being exposed.
Rashes can result from indirect contact from tools or pets, as well as through inhaling the smoke from burning these plants. If this happens, respiratory passages can react, with potentially life-threatening results. As with most allergies, it is the second exposure to urushiol, which causes the contact dermatitis.
When exposure has occurred, a red and itchy rash will begin to appear, often in the pattern of where the leaves touched the skin. In most people, the allergy to poison ivy is manageable. However, for someone who has a high sensitivity to it, even a hint of the poisonous sap can cause a problem.
In severe cases, dangerous swelling and a shutting down of the respiratory passages can occur, making breathing difficult. Other severe symptoms include rashes which cover a large area of the body, or which reach sensitive areas like the genitals, lips, or eyes. Developing fevers, painful or oozing blisters are also cases where medical help is needed immediately.
Learning to identify these poisonous plants will help prevent being exposed to them, as will avoiding areas where they grow and removing them from your yard. When hiking in areas where they grow, wear long sleeves and long pants, and be sure to change them before going back into the house. Urushiol can brush off onto animal fur, so keep pets away from the danger zones, and clean them thoroughly if they have been exposed.
Most poison ivy problems will go away after a week or so, and relief from the itching can be had from calamine lotion and cool water. However, if a reaction persists for thirty days or more, see a medical professional for help.