Poison ivy is often difficult to avoid. Even if you don't directly brush up against the plant, you can get poison ivy from touching a garden tool, ball or even a dog or cat (animals don't have the same sensitivity) that has urushiol on it. Some creams containing the ingredient bentoquatum can block urushiol and offer some protection before poison ivy exposure. Still, your best defense is to stay away from poison ivy and to get rid of it in your yard.
But the plant is not an easy foe to clear. If you spray it with a weed killer, you may destroy the poison ivy, but you must be careful not to harm other plants around it that you want to keep. Your other option is to remove the poison ivy by hand; pull the plants out from the roots, because any trace of a plant you leave behind can regrow. The key also is to wear a long-sleeved shirt, long pants, gloves and boots to avoid any contact with your skin. Immediately remove your clothes after you finish and wash them with soap and water. And take a shower for good measure.
Never burn poison ivy plants; the urushiol vaporizes when heated and when it gets into the smoke, it can severely irritate the lungs when breathed in.