Poison Ivy can grow with a plant stem, in a vine or with a woody stem - all will cause the reaction. The main thing is it has three smooth edged leaves.
Sunlight soap seems to work well at removing the oils - maybe because it is a strong soap with no oils or moisturizers added itself.
The Jewel weed or Touch-Me-Not plant (same thing - its often called Touch-Me-Nots as in the fall the seed pod explode when it is touched) works well too after you have the reaction. It doesn't always grow near the poison ivy but often does. It can also be found near water sources.
1st Orleans Pathfinders
The thread on another list started off with a lady saying that she used to wash with Octagon Soup (a laundry soap in bar form), to protect herself from Poison Ivy when she camped as a kid. (And has been doing it for the past 40 years.)
I have done some reading about poison ivy
(on the net, where else?). They do not mention soap! They do say though that if you wash within 5 minutes of being exposed you will not have a reaction!!! Even rinsing off in a mountain stream is better than doing nothing. This was the best site I found for pictures of both Poison Ivy (in two of it's colours, it turns bright red and orange in the fall!) and the other plant (Jewel Weed) that is supposed to be the antidote! (No side effects with this antidote either!) Good luck!
70% of people are allergic to poison ivy, poison sumac and poison oak.
You have an allergy to the oil that the plant produces! The smoke from burning it is dangerous too and can cause lung problems. 100 year old poison ivy (dried, no less) can still cause a reaction.
You have to be exposed twice, once to build up the histamines for the second time.
This one site quotes people as saying that some kind of flower (Jewel Weed) which grows next to poison ivy in many places is the perfect antidote. You crush the leaves and stems and use the juice on the spots that you were exposed.
Once you are exposed, immediately wash your hands. Because it is an allergy to the oil that the plant produces you can spread the oil around and cause other non-exposed spots to be exposed. You generally react the next day - so knowing what poison ivy looks like is important! (You will not spread it around by scratching the effected spot once the oils are gone!) Wash your clothing and the dog too!