Oh I hate poison ivy and because we typically don't get very cold here in the South, poison ivy is something you cant catch year round.
I have had it many times, growing up in the countryside. My mom would always make me take a bath as hot as I could stand it. Then she would rub me down with Calamine lotion. And it wouldnt itch hardly any.
Now if I come into contact with it I just use me some Aveeno anti-itch cream with the natural Colloidal oatmeal. ( it is a permanent part of my 1st aid kit) Works just as good as the Calamine lotion.