Poison oak is an allergy-inducing plant that grows mainly in the Southeast and on the West Coast, according to the Centers for Disease Control. The allergy-causing substance in poison oak is an oil called urushiol, which is present in all parts of the plant, including leaves, branches and roots. Contact with this oil results in undesirable reactions for those allergic to it. About 85 percent of people are allergic to poison oak, according to the American Academy of Dermatology. Allergic reactions can last several weeks.
Identification
Identifying a poison oak plant can prove difficult, as it grows differently depending on its geographical location and can change color with the seasons. Typically, poison oak grows as a shrub with three leaves. The West Coast varieties may resemble a vine. Poison oak plants can grow yellow or green flowers and light-green to white berries, according to the Centers for Disease Control. In the spring, the leaves are bright green. During the summer, the leaves start to develop a reddish tint, and by fall they are red.
Symptoms
Contact with poison oak results in an itchy, red rash within 12 to 72 hours, according to the American Academy of Dermatology. The rash will be followed by swelling and a streak-like appearance. Different-sized bumps and blisters will appear. Eventually, these blisters will ooze clear fluid.
Treatment
Once a rash appears on the skin, clean the area well with soap and lukewarm water. If the rash covers a large area of the body, an oatmeal or baking soda bath may help reduce itching and discomfort. Apply cortisone creams after cleansing to keep itching to a minimum. It is important not to scratch the areas to avoid rupturing blisters. Cold compresses and ibuprofen may reduce swelling. If the rash is severe, it may be necessary to see a doctor for a prescription-strength cortisone cream or oral anti-inflammatory medication, according to the University of California, Santa Cruz Student Health Center. Wash all contaminated clothing and household items.
Contraction
Allergic reactions occur only after direct contact with the urushiol oil. This can happen by coming into contact with the poison oak plant, touching something that has oil contracted the oil, such as a pet or clothing, or inhaling the fumes of a burning poison oak plant, according to the Centers for Disease Control. A rash will form only where the oil has come into contact with the skin. Scratching will not cause the infection to spread. Poison oak is not contagious. Once a rash is visible and the urushiol oil has absorbed into the skin, poison oak cannot be spread from person to person.
Prevention
The best prevention of a poison oak allergic reaction is education. Learn what the plant looks like and avoid contact with it. Wear long sleeves and long pants along with boots and gloves when going into wooded areas, according the Centers for Disease Control. Stay on cleared trails. Always wash the hands and body thoroughly after outdoor exposure. Do not burn plants that are unfamiliar.
