I have had bouts with Poison Ivy and Oak for over fifty years, and always when I go and play in all the wrong places.
Currently, I am trying to beat one without going to the doctor.
In our area, Ivy has leaves with rounded edges, Oak has a leaf with scalloped edges. It's kind of like comparing a rounded leaf of a Ash tree to the cut-out leaf of a Red Oak.
As many times as I have contracted poison ivy or oak, and after it has shown up as blisters, I know the best thing to do is scrub the infected area very hard and dry it. Use Fel's Naptha laundry soap or whatever.
Something new I bought today; try Googling "tecnu". It has a very interesting history, but I have no track record on it as far as poison ivy goes.
If you have a bad out-break, time to visit the doc. Jewel weed grows in my area, but I have not had much luck with that crushed plant.
Hope the itching subsides, Roger