Have you ever been exposed to a plant of the toxicodendron genus? You probably know them better as poison ivy, poison sumac and poison oak. If you had been exposed to one of them, you would know it, because they cause severe allergic reactions, sometimes as serious as large blisters which could require hospitalization.
Once you have been exposed, you also run the risk of spreading the oil that causes the rash if you touch or scratch the affected area, since the oil tends to cling on to the area.
Your best protection is to learn how to identify these plants and then exercise extreme care when dealing with them. Dead and wilted plants can still be toxic. Burning these plants is also very dangerous, since the smoke could cause some very serious respiratory problems. Even if you wear a breathing mask to protect yourself, the smoke could easily travel into your neighbors yard and pose a danger to them. If you ever have to remove these plants, make sure you are protected from head to toe, not leaving any skin exposed.