If you know you were in poison ivy wash with our soap ASAP,
usually that will prevent you from getting poison ivy.
If you break out in poison ivy wash affected area thoroughly, then rinse it off and apply a layer of wet soap, let it dry on your skin. Anytime it starts to itch rewash and follow steps above. Best to do this many time the first few days of break out for best results.
Lavender essential oil also helps to relieve itching.