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How to Identify Poison Oak

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Few things can beat the freedom of spending an afternoon hiking through the Californian wilderness. It's a wonderful escape from the noise of the world. One of the quickest ways to spoil that fun is an accidental contact with a patch of Poison Oak. Simply brushing against these plants can leave a hiker with two or three weeks of relentless itching, scratching, and tremendous frustration. These plants are found practically everywhere on the west coast.

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“They are weeds that grow along roads, trails, and streams. They can grow as climbing or trailing vines and shrubs.” Dr. Andrew D. Breithaupt is a resident dermatologist at UCLA Medical Center in Los Angeles. These plants are “encountered all along California, Oregon, Washington and Nevada.”

Dr. Breithaupt is comfortable outdoors, having hiked in many areas of the United States. He's traveled through trails and forests around Virginia, Half-Dome at Yosemite National Park, and the coastal regions near Santa Barbara, California.

The best defense against an accidental contact is to remember the shape and color of the leaves of these oily plants. If a hiker knows what to look for, they will be able to steer clear and enjoy the trail.

“The old saying 'leaves of three; let them be.' refers to each leaf having three leaflets and is an easy way remember how to identify the plants.” Dr. Breithaupt points out “Poison ivy and oak have three leaflets per leaf (occasionally five) while poison sumac, another important member of the genus, has between 7 and 13 (leaves). The leaves of poison ivy are oval-shaped with a pointed tip. Poison oak leaves on the west coast are also oval shaped but have rounded ends and scalloped borders. The poison oak that grows on the east coast have a bit more variable shape that can mimic white oak leaves. Young leaves are actually red in color before becoming green.” Dr. Breithaupt told Examiner.com that “Poison Ivy isn't found in California but is very common all along the east coast and mid-west, basically anywhere east of the Rockies.”

When touched, these plants transfer an irritant offensive to human skin. That passive defense is “an oil called urushiol. It is this oil that is responsible for the dermatitis or rash associated with exposure.”

Dr. Breithaupt continued, telling us “depending on the time of year the oil is either within the leaves or released spontaneously, so it can require different levels of contact, from simply brushing up against the leaf to more direct contact, to get exposed to the oil. The oil can also spread from contaminated clothing and pets. Burning the plant can even spread the oil in smoke and cause a very severe allergic reaction. It's important to note, that the fluid within blisters of the rash is produced by your body and does not spread the oil.”

The insidious problem begins when the victim touches the unknowingly contaminated patch of skin, and then transfers the oil to a separate, clean area of the body, thus tainting the new patches of skin. Fortunately, for most hikers “the allergic reaction is a delayed-type, so the rash generally does not begin to appear for at least 24 hours after exposure. Sometimes it can take weeks to appear if it is the first exposure to the plant.” the doctor told us.

This gives the hiker an opportunity to eliminate the threat of rash before it becomes a major issue. The hiker has time to clean themselves, their hiking gear, clothes, boots and boot laces before the rash appears.

So how do you know if you have come in contact with the plant if it takes hours, days or weeks for the rash to appear? Well, basically, you won't know until the appearance of the rash. By then, it's too late to react. A hiker has to be motivated enough to thoroughly clean themselves after they have made it home from their hike, just in case of exposure.

The best thing to do is be proactive in your hiking activities:

  • After every hike, wash your jackets, clothes, boots, and then take a shower. Using hot water and soap is a good defense to eliminate the oils before the rash appears. Remember, this is an effective manner to clean yourself of the oils only before a rash appears.

  • Be sure to clean any tools, gear, or hiking poles when you get home. The oils can reside on the surface of these objects for weeks. That means that if someone reaches into their closet one month after a hike, they can still become contaminated by oils sitting on a jacket or pair of boots.

  • Be aware of which plants you came in contact with while you are on the path. If you had contact with poison oak, ivy or sumac, keep a mental note of where you touched that plant. Was it with your hand, your boot, your pant leg? Remember, once you have touched one of these plants, the oils are spread by simple contact. Touching a contaminated pant-leg will probably spread the oil to your hand.

  • Use a hiking stick to move the brush away from you, instead of using your hands or legs.

Dr. Breithaupt told us “There is no bacteria, virus, or fungus responsible for the rash. The whole thing comes back to the urushiol oil. The medical name for the rash is 'urushiol-induced contact dermatitis'. What this means is the oil, urushiol, is deposited on the skin and causes an allergic contact dermatitis. This is when our own immune system mounts a hypersensitivity reaction against the oil and causes the rash.”

The doctor reminded us that “any time you start to feel ill, have trouble breathing, or display any symptoms beyond any itchy rash, you should see a doctor. Also, if you are unfamiliar with the exposure and rash, and aren't certain that it was poison ivy or oak that caused the rash, you should see a dermatologist for evaluation.”

Unfortunately for most of us, when we come in contact with these plants, we often get rashes and want to scratch. We asked Doctor Breithaupt 'what is the best thing to do if we think that we have been exposed to to Poison Oak?' He told us “wash off immediately after exposure and don't scratch the rash. Don't concentrate on just hands, wash your entire body with soap and water, as well as clothing and any pets along on the hike.” The doctor emphasized that even after you get home from your hike, you still have a bit of work you should do before you can rest.

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