As a kid I had no reaction to it at all. None. My friends and I would go somewhere and I would be the only one not to come home with it. Laugh...I thought that was just too funny...until I got it around 40 years of age. Had no idea what it was but I knew it wasn't PI. It was, and it was all over me. I guess something changed in me. But I can walk past it now and get it. I have used Tech Nu that Pat mentioned and it works ok. No jewel weed around here, but, someone told me to rub Elk Thistle on the soars. We dont have that either, but I gathered up our local thistle and rubbed the sap from it on the blisters. It helped with the itching a bit and I have used it since. Placebo maybe but if it works it works.