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Poison Ivy, Sumac and Oak

About 85 percent of the population is allergic to poison ivy, poison sumac or poison oak, and about 10 to 15 percent are extremely allergic. This is the most common allergic reaction in the U.S., and affects as many as 50 million Americans each year.

Poison Ivy, sumac and oak grow everywhere in the United States except Hawaii, Alaska and some deserts in Nevada. Although many plants have three leaves, their appearance may vary depending on location. Some have three leaves, while others have groups of five, seven or nine. Sometimes, these plants appear as a vine while in other places they appear as shrubs.

The rash caused by these plants is called an allergic contact dermatitis. It is caused by a substance called urushiol (you-ROO-shee-ol) in the sap of the plants. Sticky, colorless and odorless urushiol is very easily spread - you don't need to actually touch the plant itself to come in contact with it. It can be carried on the fur of animals, on tools or sports equipment - just about anything that came into contact with the poisonous plant.

Urushiol causes redness and swelling followed by blisters and severe itching. The rash takes about two weeks to heal, provided infection with bacteria does not occur.

Prevention is the best cure for poison ivy. Wear long pants and long sleeves when you are in an area where poison ivy is growing. If you come in contact wit a plant, wash all exposed areas with soap and running water as soon as possible. If you do this within five minutes after exposure, you can remove the urushiol. When you get home, wash all clothing outside with a garden hose to get rid of the urushiol. If you develop a rash, avoid scratching. Try cool showers and calamine lotion or hydrocortisone cream to relieve the itching and speed healing. Soaking in a lukewarm oatmeal or baking soda bath helps to dry blisters and ease itching. If the rash is severe, the doctor can prescribe medications to help treat it.

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