It is actually not that common to see a poison ivy rash on the palm or front of the hand: the skin there is very thick with callouses so the plant oil usually can’t penetrate.
But in this case the oil clearly did get through. If you yank the vine and scrape the hand when you do, you give it a path right into your system.
If this person had rubbed their face with all this oil on their hand they could have ended up in the hospital.