Poison Oak Myths

Poison oak, or toxicodendron diversilobum, is a leafy plant that is well known for causing an itchy, irritating allergic reaction to the skin. The rash caused by poison oak can spread out of control quickly if not treated properly, so it is important to separate poison oak myth from poison oak fact. This will ensure you handle any encounter with this toxic plant properly.

Identification

• The poison oak plant has three green leaves per stem, with the leaves resembling those found on an oak tree. The plant grows as both a low and high shrub and flowers during the fall months of August through November. During the fall, the leaves of the poison oak shrub change colors, turning from green to yellow to red.

Features

• The poison oak plant produces oil called urushiol. Urushiol oil is responsible for the rash that results from poison oak, ivy and sumac. Many people believe that only the leaves of the poison oak shrub contain urushiol oil. However, all parts of the plant including the leaves, stems, berries, flowers and roots contain the rash-producing compound.

Sensitivity

• A common myth surrounding the poison oak plant is that a person allergic to the plant will always be allergic to it. This is not true. An individual's sensitivity to poison oak can change over time, and immunity to the urushiol oil may develop.

Effects

• Contact with the urushiol oil will cause those sensitive to the plant to have a reaction. Wearing protective clothing may not prevent an outbreak of the rash if you touch clothing that has been contaminated with the oil.

Contamination

• The poison oak rash is only caused by contact with the actual urushiol oil of the plant. Blisters caused by the rash do not contain the oil, so scratching at poison oak blisters will not cause the rash to spread. Additionally, poison oak cannot be passed from one individual to another once the urushiol sap is washed from the body.

Warnings

• Urushiol oil can remain active on any surface it has come in contact with, including clothing and plants, for up to five years. Even contact with dead or dormant poison oak plants can result in an allergic outbreak.