"My theory is that it (poison oak) is sentient and has a collective, malevolent, intelligence. I also believe it is capable of reaching out and grabbing one's ankles when hiking on a trail." - September 1997 Wildland Firefighter Magazine

The poison oak rash is caused by an allergic reaction to a chemical called urushiol. It is present in every part of the plant, and when you touch it the oil is absorbed into the skin. The rash is the result of your body's immune system mobilizing it's forces against the invader. It first causes severe itching, evolves into inflammation, and then blistering when scratched. Urushiol can also be inhaled if the plants are burned. The smoke may expose not only the skin, but also the nasal passages, throat, and lungs. Inhaled urushiol can cause a very severe allergic reaction.

You can get poison oak by touching any part of the plant, or by touching something else that has touched the plant, such as your dog, clothing, etc. If the oil is on your hands you can spread it to any place else on your body you touch. The rash may appear first in areas where the concentration of oil is higher, and a couple of days later in other spots. Once the oil is off your hands and body, you cannot spread the rash by scratching.

An allergic reaction to a poison cannot be cured, but the symptoms can be treated. You may take cool showers and apply an over-the-counter product, such as calamine lotion, to help relieve the itch. Be sure to wash any clothes that may have come in contact with the oil. IF your reaction is more severe or involves mucus membranes you may need a prescription medication, such as prednisone, to help control the reaction. Most rashes caused by poison oak are mild and last 5 to 12 days. In severe cases, the rash can last 30 days or longer.

Prevention is the key. Learn to identify poison oak. Remove these plants from around your home. Cover your skin as much as much as possible by wearing long pants, long sleeves, shoes, and socks, when walking in the woods or working in areas where these plants may grow. Do not let pets run in wooded areas where they may be exposed to the poison.

The poison oak of the U.S. pacific coast (R. diversiloba), is a shrub or sometimes a climbing plant that can grow to 8 feet high. It's leaves contain 3 leaflets, which are toothed or lobed and hairless. Poison oak is not usually found above 4000 feet elevation.