I used to be very allergic to it also. One of my grammar school pictures shows me with a very swollen face from poison ivy. If I touched it at all, I'd break out anywhere and everywhere I'd ever had it before. Would end up at the dermatologist with steroids and shots. NOT ANYMORE.
We still have a LOT of poison ivy on our two acres. One winter, I accidentally pulled a bit of dry weeds with my bare hands, and there was poison ivy in it. No leaves, but every part is poisonous. I broke out, but a lot less than usual. This happened a couple more times, and by spring, I barely broke out at all when I got into it. I assume that is similar to taking the preventive shots. Not necessarily recommending this to anyone who is highly allergic; just relating what has happened with me.
When I know I've touched it but don't want to go into the house right away, I'll rub soil into the area. I believe that dilutes the oils. Then when I go in, I flush the skin alternately with very warm soapy water, then alcohol, several times. Usually don't get it at all that way. If and when I do break out, I scratch it open and treat it with alcohol. Stings like crazy, but takes away the itch. Do that several times a day. It goes away much, much faster than with the dermatologist treatments. I do also take Benedryl.