How long does it take for a poison ivy rash to develop and start itching?

Usually a day or so: The chemical in the poison ivy plant that causes the problem in many people usually takes a day or two before it fully erupts. Often, people feel something is a little different for a day or two before the itch and rash starts. Once there, it takes about 7-10 days to run its course.New blisters will appear and finally crust over.The rash is not contagious!the source is-clothes, gloves, etc.