MISSISSIPPI STATE -- The itching and scratching associated with poison ivy rashes can sometimes be avoided if those seeking the outdoors learn to identify and kill the vine.

John Byrd, weed scientist with the Mississippi State University Extension Service, said a mild winter and early warm weather allowed poison ivy to be more advanced earlier in the year than it normally is.

"Be extra vigilant in fighting it, especially if you have small kids or pets," Byrd said. "The oil that spreads the rash is found in the root, stems, leaves, flower and fruit of the poison ivy. Any clothing, pet or tool brushing up against it can damage the plant enough to release the oil and give you an outbreak."

Jane Clary, associate Extension professor in MSU's School of Human Sciences, said the urushiol oil in poison ivy causes an allergic reaction when it contacts skin. According to the American Academy of Dermatology, 85 percent of the population will react to poison ivy, oak or sumac.

"The severity varies from person to person. Some people don't break out in a rash the first few times they're exposed to it, but begin to after repeated exposures," Clary said. "If you know you've been in poison ivy, wash really good with soap and water to wash the resin off."

Once a rash and blisters have developed, treat a mild case with a cold water compress, cold showers, or baking soda or oatmeal baths to dry the blisters. Over-the-counter remedies include Burow's solution, cortisone cremes or Benadryl, but a person should seek medical attention if the rash is on the face, genitals or large parts of the body.

"Physicians can prescribe medications to reduce itching and inflammation, and can administer an antibiotic if an infection results from scratching the rash," Clary said.

Poison ivy can be identified by its three leaves on each stem and a vine with hairy-looking, aerial roots on the stem. Poison ivy produces small, white, inconspicuous flowers, and its fruit looks like clusters of miniature grapes that mature to a waxy green. It is found throughout the state, unlike poison oak, a bush with similar leaves that is found primarily in the hills along the Delta and in South Mississippi's coastal plains sands.

The weed scientist said poison ivy is often confused with the harmless Virginia creeper or Virginia pepper vine, both five-leaved vines that sometimes appear to have leaves of three.

The best way to rid an area of poison ivy is with a fall application of a glyphosate or triclopyr product. Byrd said applications are most effective when the plant is developing fruit, as this will sterilize the seed and maximize herbicide movement into the root where the plant is storing nutrients for winter.

"If possible, kill poison ivy chemically. If it's in an area that could be easily contacted, remove the plant vegetation carefully because even the dead, woody tissue contains the oil in it, and you can still get a poison ivy outbreak from handling dead tissue," Byrd said.