How do I cure contact dermatitus or popularly know "poison ivy" ?

Since I have had variations of what we usual call poison ivy, I am only sure that it looks like that with blisters, red spots, and white heads all over my arms. I think it is still spreading. I tried calamine lotion, benedryl and a new solution to wash it off. This has not worked. Should I give up after a week and go to a dermatologist or other doctor? Or is it best to just itch and let it run its course. I have always been extremely sensitive to these poisonous plants and to my regret I decided to pull up a plant that was suspicious looking, but did not seem to be poison ivy as the leaves were not the familiar three together and the plant had long purple flowers. I am still trying to figure out what it was, but mostly want to stop the spread of the blisters and itching. Any good, proven ideas?

How do I cure contact dermatitus or popularly know "poison ivy" ?
I understand. I normally get poisen ivy REALLY bad around this time of year. And I mean REALLY bad, like face swelling up to twice it's normal size. My mom mixes bleach with water, and this soothes my skin, and helps with the itching. I think she mixes it like, one part bleach, and seven or eight parts water. Try less bleach first, before adding more. I actually got burned from the bleach once. This works pretty good, it is the best thing I have found, besides a shot. Just be really careful with the bleach. It normally takes a while, anywhere from a week to a month. I also use it as a protection, if I think I might have gotten close to poisen ivy, then I will rub this stuff on me, and it normally works in protecting me from it. Hope this works for you!