Poison ivy (Toxicodendron radicans) is endemic to the east coast US. I have to be careful walking in the woods in the summer, as repeated exposure has made my reaction increasing severe over time. Brushing up against the leaves of the plant with bare skin is enough to cause a reaction. (I get large red rashes that blister over and weep, and take about 2 weeks to resolve - not attractive!)
I once, years ago, traveled to Europe soon after being exposed to poison ivy, and I had a particularly bad reaction while I was over there. Since poison ivy doesn't occur in Europe, my explanations of my affliction were met with blank stares and slow edging away. Probably though I had leprosy or something.....
Tom