Searching for a geocache often involves some hiking in wooded or wilderness areas and this increases the risk of coming into contact with poisonous plants such as Poison Ivy, Poison Oak or Poison Sumac.

Perhaps one of the most commonly encountered forms of poisonous plant, approximately 85% of those that come in contact with Poison Ivy will develop an allergic reaction to the oil (urushiol) the plant secretes. Extremely delicate, the plant breaks easily and oil may be secreted from the tiniest breaks or hole in the leaf or stem. Because coming into contact with dangerous fauna or flora at some point while in pursuit of those elusive caches is pretty much a given, knowing what to look for can be half the battle. There is an old saying "Leaves of three ... let it be". This is good advice, but there is more to it that many do not know and that is that while poison ivy and poison oak do in fact have three leaves per cluster, poison sumac can have any where from seven to thirteen leaves on each of its branches.

Urushiol that's rubbed off the plants onto your skin, clothing and other items can remain potent for years depending on the environment. If the contaminated object is in a dry environment, the potency of the urushiol can even last for decades. Even if the environment is warm and moist, the urushiol could still cause a reaction a year later.

Once exposed preventing the spread can be very difficult. If you have been exposed to poison ivy, poison oak or poison sumac, then try some of the steps below to help reduce the spread. If possible, stay outdoors until you have at least completed the first two steps:

First, cleanse all exposed skin with generous amounts of isopropyl (rubbing) alcohol. (DO NOT return to the woods or yard the same day as the alcohol removes your skin's natural protection along with the urushiol and any new contact will cause the urushiol to penetrate twice as fast.)

Second, flush skin with plenty of water (NO soap). If you're outside, then chances are you will only have cold water available, but this is OK as water temprature is not important.

Third, take a regular shower with soap and warm water. Do not use soap before this point because the soap will tend to pick up some of the urushiol from the surface of the skin and just spread it around.

Next clothes, shoes, tools, and anything else that may have been come in contact with the urushiol should be wiped off with alcohol and water. Be sure to wear gloves or otherwise cover your hands while doing this and then discard the hand covering.

There are also a number of Over-the-Counter products you may purchase which can help dry up the oozing blisters making the reaction a little easier to live with until it subsides. thes include things like aluminum acetate (Burrows solution), baking soda, Aveeno (oatmeal bath), aluminum hydroxide gel, calamine, kaolin, zinc acetate, zinc carbonate, and zinc oxide to name a few. As always, consult with your doctor or pharmacist to see what is best for you.

Another thing to remember is that contrary to popular opinion, only exposure to the oils secreted by the plant will produce an allergic reaction and rash. The oozing blisters or rash while not pleasant to look at are not, in themselves, contagious. All in all, the best prevention is to avoid the plants when at all possible and when in the woods protect the arms and legs with proper clothing. So that you know what to look for (and avoid) before you grab your GPS and topomap and head out the door, we recommend you visit this site which contains a wealth of information and some excellent photos.