In order to avoid a terribly uncomfortable poison ivy rash, it’s important to understand what causes the rash in the first place. The true culprit is Urushiol oil, an invisible greasy discharge found on the leaves of poison sumac, poison oak, and poison ivy that can cause skin to blister and itch. The best defense against poison ivy isn’t just avoidance, it’s the effective removal of Urushiol oil from the skin. In this video a scientific expert on skin inflammation who has spent the better part of a decade working everyday in the woods shows how to correctly remove the nasty oil and keep the rash at bay.