Poison Ivy...Outsmarting Poison Ivy and Its Cousins
What is poison ivy, poison oak, and poison sumac?
The Summer is
upon us and so are those nasty rashes from brushing up against poisonous plants
such as poison ivy, poison oak, and sumac. Approximately 85 percent of the
population will develop an allergic reaction if
exposed to poison ivy, oak or sumac, according to the American Academy of
Dermatology.
Usually, people develop a sensitivity to poison ivy, oak or sumac only after
several encounters with the plants, sometimes over many years. However,
sensitivity may occur after only one exposure.
The cause of the rash, blisters, and infamous itch is urushiol (pronounced
oo-roo-shee-ohl), a chemical in the sap of poison ivy, oak and sumac plants.
Because urushiol is inside the plant, brushing against an intact plant will not
cause a reaction. But undamaged plants are rare.
Poison oak, ivy and sumac are very fragile plants, and stems or leaves broken
by the wind or animals, and even the tiny holes made by chewing insects, can
release urushiol.
Reactions, treatments and preventive measures are the same for all three
poison plants. Avoiding direct contact with the plants reduces the risk but
doesn't guarantee against a reaction. Urushiol can stick to pets, garden tools,
balls, or anything it comes in contact with. If the urushiol isn't washed off
those objects or animals, just touching them--for example, picking up a ball or
petting a dog--could cause a reaction in a susceptible person. (Animals, except
for a few higher primates, are not sensitive to urushiol.)
Urushiol that's rubbed off the plants onto other things
can remain potent for years, depending on the environment. If the contaminated object is in a dry
environment, the potency of the urushiol can last for decades, says Epstein.
Even if the environment is warm and moist, the urushiol could still cause a
reaction a year later.
Almost all parts of the body are vulnerable to the
sticky urushiol, producing the characteristic linear (in a line) rash. Because
the urushiol must penetrate the skin to cause a reaction, places where the skin
is thick, such as the soles of the feet and the palms of the hands, are less sensitive to the sap
than areas where the skin is thinner. The severity of the reaction may also
depend on how big a dose of urushiol the person got.
What can you do to avoid poison ivy, poison oak, and poison sumac?
Learn what poison ivy looks like and avoid it. While "leaves of three,
beware of me, is the old saying, "leaflets of three, beware of me" is even
better because each leaf has three smaller leaflets.
Wash garden tools regularly, especially if there is the slightest chance
that they've come into contact with poison ivy. If you know you will be working
around poison ivy, wear long pants, long sleeves, boots, and gloves.
Hikers, emergency workers, and others who have a difficult time avoiding
poison ivy may benefit from a product called Ivy Block, made by EnviroDerm
Pharmaceuticals Inc.. It's the only FDA-approved product for preventing rashes
from poison ivy, oak, or sumac. The OTC lotion contains
bentoquatam, a substance
that forms a clay-like coating on the skin.
If you come into contact with poison ivy, oak, or sumac, wash the skin in
cool water as soon as possible to prevent the spread of urishiol. If you get a
rash, oatmeal baths and calamine lotion can dry up blisters and bring relief
from itching. You can also
talk to a health care professional about medicines
that may help.
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