Poison Ivy
|
common name
|
Poison Ivy
|
|
Also called
|
N/A
|
|
scientific name
|
Toxicodendron Radicans
|
|
classification
|
Plantae - Magnoliophyta - Magnoliopsida - Sapindales - Anacardiaceae
|
|
hazard type
|
skin irritant
|
|
range & frequency
|
Ubiquitous throughout North America (except extreme polar and desert climates)
|
Description
The best reason to fear the woods (and the fields, and the beach, and anywhere else plants can grow), especially in the dark, is not some bloodthirsty beast but this harmless-looking plant. The slightest touch triggers an unbearably itchy rash - though usually not until hours or days later. Scratching the itch spreads plant's oils, thus spreading the rash (sometimes to embarrassing and excruciating locations). Persistent scratching can lead to secondary infections. Though individual reactions vary, the itch is, in my estimation, worse than chickenpox.
The oily toxin produced by this plant is called uroshiol, and mere nanograms of it suffice to cause a rash. This oil remains capable of triggering a reaction even when the plant has been dead for up to five years. As the reaction is essentially an allergic one, individual responses vary. The amount of exposure is obviously important, and the sensitivity of the skin is a major factor. As a child at summer camp I had built up such thick callouses on my hands that I was able to pluck poison ivy with impunity, but accidental exposure is usually to the legs. Exposure can also occur by inhalation of brushfire smoke or lawnmower clippings - and a rash inside the airway can sometimes be fatal.
Poison ivy grows almost anywhere, needing only a little light and water but equally happy in damp soils or in the full glare of the sun. It usually grows as a spreading or climbing vine, but can grow as isolated leaflets in grassy fields or as a free-standing shrub. It particularly likes areas where there is a break in the forest canopy - this means roadsides, fields, and parking lots.
Poison ivy's leaves always occur in clusters of three. The leaves are lance-shaped with visible veins, hairless and usually smooth-edged. Sometimes a waxy or oily sheen is detectable, and the youngest leaves are often reddish. Flowers are small and usually go unnoticed; small round berries hang in loose clusters, turning from green to waxy white.
Mitigation
1. Avoidance
Learn to recognize poison ivy. "Leaves of three, leave it be." Poison ivy's three-leaf clusters are distinctive. The only plant that sometimes causes confusion is blackberry, which has thorns (poison ivy does not).
If you see poison ivy, DO NOT TOUCH IT. Do not touch anything which has touched it. Do not touch anything which has touched anything which has touched it. Am I making myself clear?
2. Protective Clothing
If you are in area (ie, outdoors) where you suspect poison ivy may be present, wear shoes, socks, and long pants to minimize the risk of accidental contact. Be sure to wash these before bringing them into contact with your skin or with other clothes. Keep in mind that poision ivy is a climbing vine, so watch what you brush with your arms, shoulders, face, etc.
3. Treatment
First, wash the exposed area (and any area or clothing suspected of exposure) thoroughly with soap and water. It is crucial to remove the oils as early as possible.
Next, ignore the itching as much as possible. It will go away in a few days. To prevent secondary infections caused by scratching, it is customary to give topical treatment to control itching. Lidocaine is the traditional first resort, but this is often insufficient. Corticosteroids have worked well for me. Covering the rash with a bandage or tape will prevent scratching and may speed healing. Try your favorite home remedy, and let me know if it works. Consult a doctor if rash appears inside the eyes, nose, mouth, or any other bodily orifice, or if rash persists for more than a week, or if you see signs of infection.
Conclusions
Poison ivy is an unfortunate fact of life in North American temperate zones, and that most definitely includes New England. Keep a sharp lookout in fields, woods, beaches, empty lots, construction sites, and parking lots. Exposure is almost never fatal, but you may find yourself wishing it was.
Reference Materials
Wikipedia: poison ivy
