I have a goat-driven brush clearing business. I am highly allergic to poison ivy and get it constantly. Over the years, I've gotten better at avoiding and controlling it. When I do get it, here is what saves my life and sanity. It's magic, it works. I PROMISE.
Put the afflicted area under the hottest water you can endure. Hold it there. After 1-2 minutes, the itch will accelerate like crazy, but just for a few seconds. After that, the itch will be gone for 10-12 hours. As it was explained to me, which may or may not be accurate: The hot water causes your skin to flood the area with the histamines that cause the itching. After the "flooding" it takes your body a period a time to generate new histamines and you are itch free for that time. You can also use a blow dryer on the hot setting to get the same effect, but I find the water more effective.
I researched poison ivy to the ends of the earth and nothing works like the hot water treatment (except steroids from the MD). Taking an anti-histamine is somewhat helpful in conjunction with the hot water, but the hot water is the key. BTW, I'm talking hot tap water, not boiling water. No need to burn yourself in the process. The hottest tap water you can barely tolerate is hot enough to take away the itch.
= new reply since forum marked as read