Never got into poison-ivy, but I have poison-oak. That stuff is no fun either.
I've had both. Happens in my line of work. Oak is worse IMO though.
The absolute worse case of poison oak I had I got from climbing a tree to get my favorite fishing lure back.
This tree was a menace and claimed a couple dozen lures over the years. Finally it claimed a lure I had made myself and was my favorite. There was no way to fish this thing wrong. About the only thing I didnt do with it is fly fish it.
Well one day I cast and released a tad too early and around the branch it went. I looked at it lined up to about 6 other rigs that were lined up next to it from various people. And I looked and looked and was getting more and more pissed "the hell with this Im gonna settle this once and for all" I finally said and went and got a bow saw out of my truck and attached it to my belt with a small bungee. This area around the trunk was so over grown with all kinds of stuff I didnt even notice as I was shimmying I was hugging a tree covered in the stuff till I was about 6 feet off the ground.
"Screw it. Its too late to do anything about it now" and up the tree I went, retrieved my lure and a few others then cut the branch solving once and for all that problem and shimmied back down the tree.
Now have you ever shimmied down a tree? Well if you have then you know that quite often your shirt will ride up your body exposing you from belt line to upper chest. Course I didnt think about this part when I was on my way up. I figured I'd shower it off when I got home and maybe get some on my arms and maybe my neck and that would be about it.
Nu uh. Within a few days from belt line to neck and both arms from the end of my short shirt sleeve down were noting but giant scabs. And this stuff not only itched. But literally hurt. It succccked big time. For some strange reason I only got a little bit on my face and non on the palms of my hands. and only a little on the backs of my hands.
Im guessing that because I didnt have my face buried in it going in either direction and because I kept fishing afterwards I probably washed it off my hands soon enough in the place I was fishing after handling the fish I caught.
But it was horrible.
Next time I just cut the whole tree down at the base