Poison Ivy and Other Poison Plant Rashes

With spring and summer, you may come in contact with plants such as poison ivy, poison oak and poison sumac.  With contact, most people will develop an itchy red rash accompanied by blistering of varying degrees. 


Poison ivy is common in most areas of the U.S. with the exception of Hawaii and part of Alaska.  It appears in clusters of three leaves with red stems and often grows like a vine, climbing up trees.  Leaves range from light green to dark green and turn bright red in the fall.  Leaflets have a few to no teeth along the edge.

Poison oak is seen west of the Rockies and in the Southeast.  Its leaves are divided into three leaflets with scalloped, toothed, or lobed edges.  They can resemble the lobed leaves of a true oak.  Leaves are generally bronze when they first appear, but turn bright green in the spring, yellow-green to reddish in the summer and bright red or pink from late July to October.

 Poison sumac is seen in the Northeast, Midwest and parts of the Southeast.  It grows as a shrub or small tree in moist areas and has stems with 7-13 smooth-edged leaves in pairs.  The leaves are orange in spring, green in summer, and yellow, orange, or red in fall.

Poison plant rashes cannot be spread to others by fluid from blisters or skin to skin contact.   The plant oil can stick to clothing, tools and pets and cause a rash with contact.  Plant oil can last up to five years on inanimate objects.  Oil should be removed from your skin as soon as possible with soap and water.  Removal from objects can also be accomplished with soap and water or rubbing alcohol.

The rash can appear to be spreading to other parts of the body since it is absorbed at different rates.   Spreading can occur by scratching with oil trapped underneath fingernails.

Apply over-the-counter corticosteroid creams to ease the rash and itching.  Calamine lotion, wet compresses, soaking in cool water, and oral antihistamines can offer additional relief.  Avoid hot showers or baths.

See your doctor if the rash is extensive, pus or tenderness is present, the rash spreads to your eyes, mouth, or genital area or if it does not resolve in a few weeks.

Prevention is by avoidance and wearing long sleeves, pants and gloves when exposure is likely.  Wash exposed clothing separately in hot water and detergent.  Skin barriers such as lotion containing bentoquatum can be protective if applied before exposure.  Do not burn poison plants since the plant oil can attach to smoke particles and be inhaled causing serious respiratory problems.