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Poison Ivy (poi´zen ě´ve): A plant that is a member of the cashew family, genus Rhus, that can cause an allergic reaction after contact.
What is it? (Overview)
Just the mere mention of the word "poison ivy" strikes fear into most people, and with good reason - coming into contact with these plants causes an allergic reaction (rash) in 85 percent of the population. The infamous rash is red and itchy, and there is no cure - except time. This year alone, at least 10 million people are expected to have an allergic reaction to the plant's allergen, and it could be as many as 50 million!
The cause of the dreaded rash is an oily substance located in the interior of the plant called urushiol (yu-ru-she-ol). Once a plant is damaged (i.e. stepped on or otherwise broken) the oil is released to the exterior portion of the plant. When your skin comes in contact with the oil it soaks into the skin and can cause an allergic reaction in the form of a red, linear, streaking rash. The rash usually appears within 12 to 48 hours after exposure
If you haven't had an allergic reaction to poison ivy you may be one of the lucky 15 percent of the population that is immune to it. But, it is more likely that subsequent exposures to the plant will desensitize you and cause an allergic reaction at some point in the future.
Anyone who goes outside is at risk of coming into contact with the plant and its allergen. The plant can be found in your backyard, as well as in wooded areas. Urushiol can also adhere to objects such as balls, and when picked up the oil will rub off onto your skin; or a pet can rub against a plant and spread the oil around the house. The oil can remain potent for up to a year or longer.
How do I know I have it? (Symptoms and Diagnosis)
If you suspect that you have come in contact with poison ivy and you develop a red, linear, itchy rash within 12 to 48 hours, you can be quite certain that you are having a reaction to the plant's allergen urushiol.
Other symptoms can include blisters, which eventually break, ooze, then dry out; fever; swelling and general discomfort.
The rash can appear on any part of the body that has come in contact with urushiol either through direct contact with the plant, or indirect contact, i.e. spreading the oil by touching your hand to your face or by picking up an object that has the oil on it.
The rash is less likely to appear on the palms of hands or soles of your feet because the skin is thicker in these areas and the oil cannot be absorbed as easily.)
Diagnosis is made through visual inspection of the rash, noting the presence of symptoms, and by the taking of a medical history by your doctor that explores possible exposure to the plant.)
How can I treat it? (Treatments)
Treatment of a reaction to poison ivy will depend upon severity.
For mild reactions, characterized by rash, blisters and itching, there are several over-the-counter (OTC) treatments that can provide relief. Keep in mind that there is no cure for an allergic reaction to poison ivy, but you can treat the symptoms and make yourself more comfortable until the condition runs its course, which usually takes 14 days.
Topical OTCs that can help relieve itching and dry up accompanying blisters include Calamine lotion or a lukewarm bath in Epsom salts, vinegar, baking soda or an oatmeal solution. Cool compresses on the affected areas can also make you feel more comfortable. If you are having a difficult time tolerating the itching (most people do), you can take an oral antihistamine, such as Benadryl. However, do not use a topical antihistamine because it can actually make the condition worse.
If you experience symptoms of a severe reaction such as: swelling, rash on your face or genital area, fever, extreme redness or pus; or if the outbreak is widespread (covers 20 percent of your body or more), you should see your doctor or dermatologist immediately for treatment. Your doctor may want to prescribe an oral coricosteroid such as prednisone to stop the reaction. However, treatment must be started within several hours to be effective, so if you have had a severe reaction in the past, go to your doctor without delay.
Avoid scratching the affected areas. Although scratching will not spread the rash, it can cause complications such as infection and even nerve damage.
There are currently no alternative treatments that have been scientifically approved to treat the poison ivy rash; however, natural treatments such as plantain, feverfew and jewelweed may provide some relief from the itching.
How can I prevent it? (Prevention)
One sure way to prevent a poison ivy outbreak is to avoid the plant altogether. The best way to do that is to know what the plant looks like. The old saying, "Leaves of three, let them be," is a good start, because poison ivy usually has three leaves. Unfortunately, identifying poison ivy is not as easy as simply counting to three.
Poison ivy looks different from season to season. In the winter the plant has no leaves, but can be identified through the presence of greenish-white berries. When the plant does have leaves they will be oval in shape, and can have smooth or toothed edges. In the summer the leaves are green in color, in the spring, red and in the early fall they take on the common colors of autumn and can be yellow, red or bronze. The plants may also have small flowers that can vary in color from cream to yellow-green. If you see leaves that have black spots on them, this is a telltale sign that urushiol is on the plant, so definitely stay away!
When outdoors, wear long sleeves and long pants, socks and shoes, whenever possible. For added protection, you may want to visit your local drugstore and purchase a product called IvyBlock or StokoGard, both of which bind to urushiol and prevent it from soaking in to the skin.
If you think you have come in contact with poison ivy, immediately rinse the exposed skin with water; if you are outdoors, water from a lake, stream or garden hose can be used. Then, pour rubbing alcohol over the skin. Do not use pads or rub the skin as this can spread the urushiol to other areas. Wash all clothing in the washing machine with soap, being careful not to re-expose yourself to the irritant. Also, wash any garden tools or other objects that may have come in contact with the plant. If you think your pet has come in contact with the plant, you will need to give him a bath to get rid of the oil. Don't worry, though, urushiol does not affect pets.
Frequently Asked Questions (FAQ)
Q. Am I safe from exposure when a plant is dead or when it's extremely cold outside?
A. No. Even a dead plant can have urushiol on it and cause a reaction. Extremely cold weather does not have an effect on the oil's potency either.
Q. Is the poison ivy rash contagious?
A. Contrary to popular belief, the rash is not contagious. Scratching also cannot spread it, nor can the fluid from blisters. What does spread poison ivy is spreading the oil to other parts of your body, i.e. if your hands are exposed to the plant and you unsuspectingly touch your face.
Q. If I find a plant should I dispose of it by burning it?
A. No. The urushiol is carried in the smoke and when inhaled can cause serious respiratory inflammations. The best way to get rid of poison ivy is by using an approved herbicide.
Where can I find more information? (Resources)
Resources
www.aad.org (American Academy of Dermatology)
Resources
American Academy of Allergy, Asthma and Immunology
www.aaaai.org
Food and Drug Administration
www.fda.gov
National Institutes of Health
www.niaid.org
Glossary
Dermititis: inflammation of the skin
Urushiol (oo-roo-she-ol): a clear to pale-yellow oily substance that is located throughout the plant's interior system and is released when the plant is compromised. Urushiol is the allergen that causes the allergic reaction, not the poison ivy plant itself. The substance is also found in poison oak and sumac.
Reviewed by, sources
"Outsmarting Poison Ivy and Its Cousins." FDA Consumer. 9-1-1996. Available on the Web at http://www.fda.gov/fdac/features/796_ivy.html
"Poison Ivy Pointers." Pediatrics for Parents. 12-1-1998. pp3.
"Poison Ivy Hazard Can Outlast Summer." Minneapolis Star Tribune, 7-7-1999. Available on the Web at www.startribune.com
"Poison ivy suddenly gets a lot less scary." U.S. News and World Report, 7-6-1998. Available on the Web at www.usnews.com
"Spotting, dealing with toxic trio of the plant world." Minneapolis Star Tribune, 7-8-1998. Available on the Web at http://www.startribune.com
"Poison Plants: Ivy - Sumac - Oak" American Academy of Dermatology Patient Pamphlet, 1999. Available on the Web at www.aad.org/aadpamphrework/PoinsonIvy.html
The Columbia Encyclopedia, Fifth Edition, 1-1-1993
National Institute of Allergy and Infectious Diseases Web site. Available at http://www.niaid.nih.gov/factsheets/poisonivy.htm
Johns Hopkins Web site. Available at http://www.intelihealth.com
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