I've always been able to touch and brush up against poison ivy and not break out. But if the leaves were crushed even a little I'd break out with the stuff. But the inflammation I got was rather mild.
I guess it's the right time to share a funny story from my misbegotten youth. I majored in Forestry in college and graduated with my 5 year degree. One professor that I dearly loved was a gruff, no nonsense guy who took us on walks through wild areas of campus; now sadly all paved and built upon.
One days class found us in a "bowl" next to one of the buildings that was a few acres in size and noted for having a great variety of plant species. He always carried a a clipper for reaching up and plucking leaves and twigs. You can guess that most of us were country boys and knew what a lot of plants were. Well, he reach up and plucked a twig with leaves from a tree trunk. Now, this great professor never smiled or laughed at his students.
He held up the clipper with the twig in the pincers and asked, "Who knows what this is"? Now we all, most of us, anyway, knew what we were looking at. One kid immediately stepped up to examine the sample. No one cracked a smile or said anything. This "city slicker" kid took the sample, studied it briefly, smelled it and said, "Hmmm, I don't know for sure". The straight faced prof announced, "poison ivy". Kinda felt sorry for the kid but I think he just chose the wrong major.