of the valley
Poison ivy is a
ten-meter-high tree. The leaves and the bark of both plants contain a very
poisonous resinous substance which has an allergenic effect. A subsequent
exposure to their poison is always more dangerous than a previous one.
The most toxic compound is the oleoresin.
sap badly damages skin after a short-lived itching. In a few hours, a rash
appears as well as reddening and swelling of parts of the body that have
been in contact with the plant. After that, itching returns accompanied
by a local sharp stinging pain.
General symptoms also include
fever, vomiting and diarrhea. There is a great risk of a lethal end after
oral intake of parts of the plant.
There are also cases
of irritation and inflammation of the skin and the mucous membrane. These
are caused by a long stay in gardens where poison ivy is cultivated as
a decorative plant. A number of medicinal substances such as tannin and
gallic acid are extracted from poison ivy. They are common ingredients
of medicines used in rheumatology, dermatology and neurology.