Poison Ivy: It's a Jungle Out There -

Q: My son went hiking with his Boy Scout troop and came home with an itchy red rash on his forearms and legs. His doctor said he'd touched poison ivy. What can I do for him?

It often happens in summer when children are climbing trees, gardeners are clearing weeds and golfers are picking up stray balls: A part of the body comes into contact with poison ivy, a plant marked by three pointed leaves. The toxic component is a resin, urushiol, found in the sap of poison ivy, poison oak and poison sumac.

Some people are susceptible to urushiol one year but not the next, and about 20 percent are completely immune to it. Nonetheless, as many as 50 million Americans are affected by poison ivy annually.

The allergic reaction begins with itchy red rashes that appear on skin that touched the plant and on the edges of fingers and other thin-skinned body parts that come in contact with the resin. This inflammation is often accompanied by swelling and by oozing blisters as small as pinheads or as large as oranges. The rash typically erupts within 12 to 48 hours of contact with the plant. A mild form usually takes 10 days or longer to heal.

Poison ivy dermatitis should not be taken lightly, says Vincent S. Beltrani, associate clinical professor of dermatology at Columbia University's College of Physicians and Surgeons in New York: "If you can't sleep at night because of the itch, it's not life-threatening, but it's most discomforting."

In 1996 the Food and Drug Administration approved the first drug that protects people from poison ivy. Called bentoquatam and marketed as IvyBlock, it's an over-the-counter lotion that must be put on the skin at least 15 minutes before exposure.

Dermatologist Jere Guin, a professor emeritus at the University of Arkansas who has studied poison ivy since the 1970s, says IvyBlock and other barrier creams are useful. But from a practical standpoint, he says, vinyl gloves--thrown away after use--are the most effective protection. Rubber gloves are ineffective, he says, and skin cleansers that claim to counter exposure to poison ivy will not help if enough urushiol has penetrated beneath the skin, which can happen in just a few minutes.

Poison ivy dermatitis has inspired many myths. Among them:

* "A poison ivy rash is contagious." Actually, the rash itself is not contagious, although the urushiol, which causes the allergic reaction, can spread from one person to another by contact.

* "If you scratch poison ivy blisters, you'll spread the rash." Jerome Z. Litt, assistant clinical professor of dermatology at Case Western Reserve University School of Medicine in Cleveland, says the rash spreads before the blisters form, in the first hour or so after contact with urushiol. This often happens accidentally, when you get the resin on your fingers, then touch your face or other parts of the body.

* "Calamine lotion is the best treatment." "I don't think it's particularly helpful," says Kathi Kemper, director of the Center for Holistic Pediatric Education and Research at Children's Hospital, Boston. "It just gives you something to do. It just gives you a pink badge that says, 'Yes, look, I'm suffering.' "

* "Topical antihistamines and topical anesthetics are helpful." In fact, Litt says, these products can prompt allergic reactions of their own.

* "You can get rid of the poison ivy problem in your yard by burning it." Don't ever do this. Doctors tell horror stories of people who get inflammation of the lungs and severe dermatitis in uncomfortable places from smoke wafting under their clothes.

If urushiol is on your clothes and you "throw the clothes in the laundry and take a bath right away with soap, you can probably minimize risk," Kemper says. She suggests washing gardening tools and outdoor gear--and even pets--that may have been in contact with urushiol, because it can cause an allergic reaction months later.

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Simple Approaches

Treatment depends on the severity of the rash, with mild cases often responding to home remedies and over-the-counter hydrocortisone 1 percent cream.

For a mild, localized rash, Beltrani's favorite remedy is putting a cold cloth on the area to relieve itching, while Kemper recommends rubbing the spot with an ice cube. Plain zinc oxide, found in diaper rash cream, may be soothing before bedtime.

Kemper, who is also an associate professor of pediatrics at Harvard Medical School, says aloe gel, cooled first in the refrigerator, and calendula cream are safe and at times effective: "It's fine to try emollients, ointments and gels, but there's no evidence they're better than the standard [hydrocortisone] cream." She also suggests soaking a cloth in a strong cup of chamomile tea and using it as a compress.

Kemper says oral Benadryl is helpful, because it often makes children sleepy and decreases their itching. But Beltrani discourages Benadryl, saying "you usually scratch in your sleep anyway." And Benadryl doesn't work on poison ivy, he says, because it's not an anti-inflammatory drug.

If the rash is widespread, baths may provide relief. Litt recommends adding oatmeal or baking soda to a warm or tepid bath and soaking for 15-20 minutes two or three times daily to ease itching and dry oozing blisters.

When topical treatments don't work, corticosteroids are the standard alternative. Oral prednisone has become a mainstay for more severe or persistent cases.

Rachel Moon, medical director of the outpatient clinic at Children's National Medical Center in the District, says the clinic treats poison ivy "fairly often," especially in the spring and summer. "If it's on the face or it's really very, very bad, we usually put [the child] on a seven-day course of oral prednisone," she says.

Scott Dinehart, associate professor of dermatology at the University of Arkansas, says it's fine to treat yourself initially. But if the condition doesn't stabilize or improve in a few days, if it's covering a large area or if it differs from previous reactions, it's wise to seek medical care. Once blisters appear, it's not uncommon to get an infection, which is marked by fever, hot skin, pus, pain and tenderness. At that point, he says, antibiotics are usually necessary.

Stephen Weiss, associate medical director of the Treehouse Center of Integrative Medicine in Albuquerque, is a board-certified family physician who considers homeopathy the best treatment for most cases of poison ivy. Under the homeopathic theory of "like cures like," he says, patients are given a minute amount of drugs that might otherwise prompt the same symptoms they're already experiencing. In the case of poison ivy, he says, a diluted dosage of Rhus toxicodendron, croton tiglium or graphites may help. If such a remedy doesn't work, he prescribes the standard medication.

Weiss echoes many of his colleagues' thoughts about Internet remedies for poison ivy dermatitis: "Most of the things you see out there, they're not going to help, but they're not going to hurt, either."

But Litt worries about dangerous information, citing a remedy that called for diluting an herbicide in water and spreading it on the skin, which could cause burns or get into the bloodstream. Less hazardous but equally ineffective is an advertisement Litt recalls seeing for a balm containing olive oil, bee's wax, St. John's wort, vitamin E, jewelweed, sweet fern, comfrey, chickweed, calendula and witch hazel. "Camel dung works much better," he jokes.

For more information about poison ivy, contact the American Academy of Dermatology at 888-462-DERM or www.aad.org/pamphlets/PoisonIvy.html.

Treatment of Choice is a weekly description of mainstream and nontraditional therapies for common ailments. To ask questions or suggest topics for coverage, send e-mail to health@washpost.com (type "treatment of choice" on subject line) or faxes to 202-334-6471. You may also reach us by U.S. mail at Treatment of Choice, Health Section, The Washington Post, 1150 15th Street NW, Washington, DC 20071. Treatment of Choice is an educational column and is not a substitute for medical advice from your physician.

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