I have had poison ivy before and I don't think that's what you had. Usually it takes a while for the oil to soak in and start causing a reaction. It took almost a full day before I really started to feel anything.
It's possible it was wild parsnip or gianthog weed. I haven't run into either of them, but they might be faster acting than poison ivy.
http://www.cbsnews.com/news/wild-parsnip-giant-hogweed-toxic-plants-to-watch-out-for/
@soaringeagle Thanks for the plant tips, I will look into it. It's funny though, I still haven't gotten rid of those persistent itchy bumps. Good day to you!