A poison ivy primer
By Karla Araujo
The Martha's Vineyard Times
May 28, 2009
It's itchy, ugly, and persistent. Along with skunks, ticks, and August traffic at Five Corners, poison ivy earns a top spot on the list of Island nuisances. Each spring, the dreaded toxicondendron radicans, poison ivy, brings victims in droves to Island pharmacies and doctor's offices.
Leaves of three, let it be. Poison ivy is among the Vineyard's top nuisances. Photo courtesy of Tim Boland Horticulturists, pharmacists, doctors and gardeners agree: The best defense against poison ivy is calculated avoidance. But even if you recognize the distinctive three-leafed plant, it's often difficult to escape its effects because the poison ivy plant contains urushiol (yoo-roo-shee-ohl), an oil that bonds to the skin. About 85 percent of mankind is allergic to it and develops an itchy red rash within one to two days after contact.
And you don't even have to touch the plant to contract the rash. Your dog or cat romps outside, comes in and rubs up against your leg, and two days later, you get it - a raised red patch of skin. A day or so later, small blisters will begin to form and the rash that can plague you for up to several weeks becomes relentlessly itchy because animals can carry the sticky urushiol on their fur without being affected.
Urushiol is found in the sap of the poison ivy plant. It's present year-round both on the berries that often remain and on the bare stems that appear to lie dormant during the coldest months. The oil is contained inside until it is compromised by crushing, cutting, or burning.
What does poison ivy look like?
"Leaves of three, let it be," the old adage warns. Be on the alert for plants that feature three leaflets which are oval and lightly toothed that start out bright green in the spring, then turn yellowish or reddish, then bright red in late summer and fall. According to Tim Boland, executive director of the Polly Hill Arboretum, the plant is sneaky and aggressive, flourishing on the Island in three forms: a climbing vine; ground cover; or a shrub.
"It thrives on land which has been disturbed," Mr. Boland says. "When a field is cleared, where there has been development or, in the case of sand dunes, where sand and wind create natural disturbances. That's why the Vineyard is such an ideal environment. It's also typically found on the edge of fields or woodlands."
Is it contagious?
Although poison ivy often seems to spread, it's actually the body's delayed reaction to contact with urushiol. The oil penetrates the skin in minutes, but the rash can take between 12 and 72 hours to appear, affecting thinner skin before thicker. According to internal medicine specialist Dr. John Lamb, medical director at Island Health Care in Edgartown, people think the rash spreads from one part of the body to another, or from one person to another, but it is only contagious if the oil itself is transferred.
Protecting against poison ivy
The best prevention, experts agree, is protection. Tim Boland of Polly Hill recommends wearing long pants, boots, and a long-sleeved shirt, just as you do to protect against ticks.
Isaac Taylor, owner of Up Island Grass & Gardens in Aquinnah, offers this advice: "Know what poison ivy looks like, especially with no leaves. People often get it worst in the winter when they think it's dormant. Watch for a plant with little balls like black pepper seeds. There's still oil on it even without leaves."
Poison ivy can be contracted from direct, indirect, or airborne contact with urushiol, one of the most powerful plant compounds known. You can get the oil on your skin by:
Touching the poison ivy plant;
Touching any clothing, shoes, or gardening tools that may have the oil on them;
Touching any pets that have been in contact with the plant and have gotten the oil on their coats;
Burning the poison ivy plant and releasing the oil from the plant through smoke.
Be prepared. It is a problem that all agree will only get worse. "I see it more than ever," Mr. Taylor says. "And I see it in places on the Island where it didn't grow before."
"It's critical to wash yourself, your clothes and tools - anything that might have come in contact with the plant - including under your fingernails, in order to contain the rash," Dr. Lamb says. "It typically appears on the face and hands first.
"When you get back inside after potential contact, use dishwashing gloves to remove your pants and other clothing and put them directly in the wash. Otherwise you can transfer the oil to the chair or other objects around you. An outdoor shower is a great idea."
Some physicians recommend applying an over-the-counter skin barrier product (such as Ivy Block) that contains bentoquatum in order to prevent urushiol from penetrating the skin.
How to I treat it?
While advocates of homeopathy, a form of alternative medicine, recommend ingesting tablets made from the leaves and stalks of the poison ivy plant itself, traditional health-care practitioners and horticulturists suggest a more conservative approach.
Pharmacist Warren Holmberg of Leslie's Drug Store suggests washing with green soap or Technu, a non-prescription cleanser and treatment that removes urushiol from the skin, followed by the application of an over-the-counter hydrocortisone cream.
"I see people suffering from poison ivy all day long. It's insane," he says. "It will run its course, but you can always get a prescription for a more potent topical steroid or, if it's really severe, an oral steroid."
At Conroy Apothecary in West Tisbury, pharmacist Tamara Hersh sells so much Technu that she recently set up a huge display of the product. "I tell people to wash themselves and their clothing in it," she says.
Ms. Hersh also reports successful results from a new over-the-counter poison ivy treatment called Zanfel. "It's expensive - about $40 a bottle," she says, "but in severe, persistent cases it seems to wash away the rash more effectively." She also recommends the application of topical hydrocortisone cream three times a day, along with a drying/cooling agent such as Rhuli-Gel.
For those who think that eating poison ivy might be worth a shot, Ms. Hersh sells the homeopathic remedy Rhus Tox. "Some people claim it works like a vaccine," she says. "They say if you take it for a few days you build up your immunity."
Ironically, Polly Hill herself, the legendary horticulturist who turned her family's 70-acre West Tisbury sheep farm into a public arboretum, reported that she ate poison ivy leaves as a child in order to build up immunity to the pesky plant. "She felt it worked," Mr. Boland says. "She lived to 100 and never got poison ivy as an adult."
Dr. Lamb's final advice? Wash your skin, clothing, and any objects that may have been affected as soon as possible after contact. Washing within 10 minutes can eliminate up to 50 percent of the oil and dramatically cut down on the severity of the rash.
"Studies show that in the last 50 years the growth rate of poison ivy has doubled," Mr. Boland explains. "The Vineyard has seen more disturbance of habitat from development as well as an increase in carbon dioxide. Poison ivy is known to grow more vigorously in these circumstances."
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