Aloe Vera Gel works the very best for me. It will curb the itching almost instantly and begins to dry up the ivy bumps. When it was really bad I would wash hard to break the blisters and then pat on the Gel. It may take a couple of days, but has always worked for me and I can get it if it is in the air. I feel sorry for anyone going through this. I don't know how it works on poison oak. Hope you can get rid of it before hot weather sets in.
Aloe Vera Gel can be purchased at the drug store.