Hun if you itch try to just rub around the area. It you pop the blisters it won't spread. I had 2 doctors and a pharmacist tell me the same thing. It all depends on where the oil touched the skin that will determine where you break out. So be sure and wash all shoes and socks and clothes that you touched when you caught it. You can get poison ivy months later if you touch somehting like a shovel or old gloves that still have the oil on them. About a year or so ago my husband and I got into a nasty patch of it and didn't realize it. I saw the oils and my skin and thought I had gotten into some kind of oil. Every place that the oil touched I broke out. As much as I scratched and as many blisters that I popped it never spread.
Here is a link with some F&Q's
http://www.poison-ivy.org/html/faq.htm