|Yes it is possible to get an internal case of it which is called a systemic reaction. Researchers are still learning what and why this happens with some people but it has happened in the following circumstances.
- oil penetrates a cut or open wound
- very high dose of oil penetrates the skin
- oil penetrates a thin part of the skin. Think thin skin over joints such as forearm.
- breathing in the oil if it become airbourne. Most common during a forest fire or from using power tools around the vines.
Generally when you breath I am told you feel it everywhere including your lungs. There is book in our books section called Poison Ivy, Pets, and People. The authors wrote me and asked me to put their book in our book section. The book was written because he "almost died from inhaling the smoke of a neighbor's burning poison ivy plants" according to his wife.