I have a reaction to poison ivy that is what most would consider excessive. After coming in contact with the plant and following all the suggestions about hot water and soap to get rid of the oil, I still end up with a rash that progresses where it wants and lasts for over 6 weeks.
The only thing I have found to work is Jewelweed. Jewelweed grows wild across North America and contains an anti-inflammatory and fungicide that is used in such medications as Preparation-H.
You can break the stem of a Jewelweed pant and get a milky substance. You can spread that substance directly on a poison ivy breakout and it will help to aid in drying out the rash and in turn helps greatly with the itch associated.
If you can not find Jewelweed, Burt's Bee's has a Jewelweed soap that you can find in most health food or natural food stores. It has been one of the only things that has helped my poison ivy breakouts. I have tried oatmeal, topical creams, and any other home remedy you can think of. The Jewelweed works.