I'm in California & we have oodles of Poison Oak. I get it when I look at it.
I've had the Prednisone shots- didn't really work for me- so over the yrs here's my 2-week sure fire cure:
1) If you know your exposed- Wash with Tecnu scrub along with Dawn dishwashing soap. - ASAP
2) Once you figure out you were exposed- follow #1 & RINSE WITH Hot water (as hot as you can stand it) for 30 seconds-I know some say you're not suppose to use hot water- but it'll burn like crazy for 29 seconds & then it'll go away.
3) once you're dry use the Calgone anti-itch ointment (not cream)
4) powder yourself down with baby powder.
This keeps the itch away for 4-6 hours- then you repeat
5) Buy Dr. Hylands Poison Oak/Ivy homeopathic pills follow the somewhat elusive directions (1st day take 1-2 pills every 4 hrs) Then take 2-pills morning / night until clears up. Here's an experienced caution- Don't take too many pills or you'll break out even worse (places you know you haven't been exposed) It is systemic. Good luck!
Just had the whole system tested again this year and it still works for me!