What is poison ivy?
Poison ivy is not a true ivy (the name is sometimes written as “posion-ivy” to differentiate), but a woody vine from the plant family Anacardiaceae. Its official name is Toxicodendron Radicans, but it is more commonly known as "poison ivy" because of its production of a an oil called urushiol, which is a skin irritant. Most people who come into contact with urushiol will experience an allergic reaction. This is urushiol-induced contact dermatitis, most commonly manifesting iteself in the form of an itchy rash.
Poison ivy is a pretty common plant, growing throughout most of North America, Canada, and parts of Mexico. It grows at lower altitudes, usually in wooded or forest areas, but is not limited to these – it can also be found in open fields, or more exposed, rocky areas. Although not able to grow in arid or desert conditions, poison ivy is not overl sensitive to soil moisture, and can therefore cope with quite a large variety of different soil types. Its durability means that it can adapt to and thrive in may different conditions, bearing up well in direct sunlight but also tolerant of shade (hence its ability to grow in abundance in forest areas).
The reason it gets called “ivy” despite not actually being one is that it often takes the form of a climbing vine, creeping along various kinds of support and even sending out tree-like branches when mature and growing on a substantial support. The plant also grows in the form of a shrub (these can reach about 4 feet in height, or 1.2 meters), and a ground cover. With its grayish white fruit a wintertime food for some birds, poison ivy is a thornless green plant with clusters of three almond shaped leaves. The plant spreads very easily, and in a number of ways – such as transfer of seeds by animals, and, in the case of the vine version, by putting out roots.
Care should be taken not to let your skin come into contact with poison ivy. About 15% of people will have no reaction whatsoever to urushiol, but for the majority of people the effects are unpleasant. It clings to the skin, causing itching that tends to be fairly severe before turning into a red-colored rash or a series of lumps. Blisters will usually follow, and in more severe cases, these will become larger blistering sores, oozing fluids. Dermatologists generally recommend antihistamines for treatment of posion ivy rashes, and for prevention of its effects, although other remedies such as Calamine lotion can often be used with success to relieve discomfort from milder rashes.
Only very serious reactions to poison ivy require hospitalization. It's just advisable not to do anything that will aggravate the situation – scratching the blisters is not advisable. If itching is unbearable, many recommend applying heat, such as from a hair dryer or hot water. Heat makes the skin release histamines, which give relief from itching. The rash can last from around one week to four weeks, depending on how serious the reaction has been, and what treatment has been applied.
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