One hyphenated word - Round-Up. Cut the vine to the ground wherever there is a main stem and put a drop or two of full-strength RU on the cut surface, making sure it covers the whole surface out to the bark. A DROP.OR TWO. No need to spray the whole vine, which I assume you will be putting into the garbage. You can pull up the seedlings, but the parent vines are a pain to get up, hence the Round-Up. If you are totally opposed to Round-Up, as some people are, you are going to have to keep chopping it down as it starts to regrow, which it will. Either way, good luck.

Anything with thorns wouldn't be poison ivy poison sumac poison oak. That being said have you tried Benadryl to calm the itch? It may be simply that you're allergic to one of the planta or something in the area.

The urushiol that causes the rash is present in all three of those plants, so anyone that reacts to one will react to all three. Poison Sumac has a very limited growth area, generally very wet places, so it is unlikely to be found where it is high and dry. But the other two do grow almost everywhere, although I have not seen any in years. Poison Ivy is a vine. Poison Oak tends to be more of a shrub and the leaves closely resemble those of Oaks, Poison Sumac is a shrub and looks similar to most of the other Sumacs.

It could be mites (plant lice), especially because they love to hide between your fingers. Does it itch worse at night? Mites are more active at night. One year, we made a scarecrow costume for my son and stuff dead grass up around his ankles and wrists. The next day, he was covered with a horrible rash halfway up his arms and legs. The doctor took a scraping and said it was plant lice, that they overwinter on dead grass. He gave us some permethrin cream and it cleared it right up, but we never did THAT again. Put some vaseline all over the rash in case it is mites. It will smother them. You can get RID for lice and rub that on those spots. Also, virgin coconut oil is very good at killing them, if you want to stay natural. I had a horrible itch on my arms once that was so painful at night that I had to put icepacks on my arms to get to sleep. I started rubbing coconut oil on my arms every night, and within a week, it was gone and has never come back.