Tannic acid either in over the counter remedies, or you can just steep tea to make a strong brew, either soak body part in it, or soak a cloth & place on skin. Frankly, I get Poison Ivy so bad, I have to go to the doctor, but this worked for me in the past with a minor case.
Be sure to wash everything! The oil can recontaminate for years. Hope yours is a mild case!!