Calamine lotion work to both dry it out and soothe the itching. Pretty well. Just bear in mind, too, that poision ivy can still cause you to break out even after it's dead because the oil that causes the allergic reaction is still in the dead plant.
I'm really allergic to poison ivy, too. I remember one time (could never forget it) as a kid a neighbor burned a brush pile with a bunch of poison ivy in it. Our house was directly downwind and I broke out over literally 100% of my body, including my private bits (ouch!)! Had to go to the doctor for a steroid shot, and I was MISERABLE for a couple days.
Mike