Poison Oak Identification

Poison oak causes itchy, painful rashes, blisters and swelling when it comes into contact with human skin. It excretes urushiol oil, which causes all of the trouble (most people are allergic to it). The best treatment for poison oak rash is to avoid coming into contact with it in the first place. Start by dressing in long-sleeved shirts, blue jeans, boots and gloves when moving through areas that contain poison oak. Beyond that, it pays to know what poison oak looks like and how to identify it before you get too close.

Habitat

• Poison oak grows throughout the western United States, though it can be found in Atlantic regions as well. It grows most prodigiously along the Pacific Coast, particularly in California, which has many oak and fir forests where it can thrive. It's usually found in shade-covered areas near larger trees, and it flourishes in damp conditions, which usually means there's a water source nearby. Sometimes poison oak can appear as a small shrub, but it also appears as a climbing vine growing on the sides of other trees.

Leaves, Flowers and Berries

• The leaves of a poison oak closely resemble those of its nonpoisonous namesake, with scalloped ridges that may cling or scratch. The adage "leaves of three, leave them be" is a bit of a misnomer, since it sometimes grow in clusters of five as well. Poison oak leaves tend to be shinier than the leaves of a regular oak, and poison oak shrubs don't grow nearly as high. The leaves will be green in the spring, gradually turning yellow and red during the summer to become bright red in the fall. Flowers bloom in the spring; they tend to be white and develop greenish white berries.

Procedure

• Both the leaves and the twigs of a poison oak are coated with urushiol oil, which means they should never be touched or brushed against. If you have some means of marking the area, do so; it prevents any subsequent wanderers from brushing against the poison oak. Any clothes which come into contact with it should be washed with hot water and detergent immediately. If you get urushiol oil on your skin, a rash will begin to develop within one or two days. Resist scratching at it, since that only spreads the urushiol oil around. Instead, treat it with hydrocortisone, calamine lotion, or skin creams with menthol. If you don't have access to them, use cold compresses to keep the swelling and irritation down. Severe cases might require a doctor's attention.