The first thing you need to do if you have touched poison ivy, poison oak, or sumac, is to wash thoroughly – right away.
But if you are really wrestling with removing stubborn vines it is very possible to cut a vine then “stab” yourself with that cut vine.
And doing so can “inject” the plant sap into your skin. Washing is still highly recommended, but the sap that is now into your skin can cause the deep, nasty rash as shown here.
So be careful when cutting the vines! Be aware that the sap which contains the urushiol oil can drip or splat everywhere, including under your skin.
And remember not to touch your face or other tender areas if there is any chance you have the plant oil on your hands.