I also have had reacuring sysmptoms. At a time of the year in New England when I would not even be outside to come in contact with the plant or oil. I would develop small rashes of PI and I know what it is as well as PO. These would be small patches usually on the back of my hands or around my wrist. I know it sounds like I may have touch some PI oil but you will just have to trust me that I did not. This went on for about 12 to 15 years. In that time though I work out doors with trees I never got a bad case of PI. Now that I dont get these yearly breakouts during off season I am getiing substantial PI rashes again from working with it. Go figure. I can't answer your question scientifically. I never asked the doctor or anyone. Thought I would just share my experience.
