I'm highly susceptible of poison ivy, have been my entire life.
I caught it so often in my youth, that the scratching must have destroyed most of the hair follicles on my legs as I have very sparse hair on them but normal amounts everywhere else.
Calamine lotion and Absorbing Junior were the weapons then; now I use Jewel weed, works great at cutting and neutralizing the Urushiol oil.
I keep the ivy at bay at my place, (the dog brings some from the neighbor's) and keep cultivated a large patch of jewel weed, an easy to grow weed also known as 'touch me not' as the seeds 'shoot' out when touched, pretty neat to walk through a patch at 'seeding' time.
It's free, just crush the stems and leaves in your hands until the sap makes it damp and rub it on, actually 'scratch' yourself with it.
Hope you find some growing nearby in a hurry.