Poison Ivy, Oak, and Sumac
Melissa Conrad Stöppler, MD
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
William C. Shiel Jr., MD, FACP, FACR
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
- Poison ivy, oak, and sumac facts
- What causes the rash? How do I identify poison ivy, oak, and sumac?
- What are the signs and symptoms of the poison ivy rash?
- Is a rash from poison ivy, oak, and sumac dermatitis contagious?
- What are risk factors for poison ivy, oak, and sumac dermatitis?
- How is the dermatitis of poison ivy, oak, and sumac diagnosed?
- What is the treatment for poison ivy, oak, and sumac dermatitis?
- What are complications for poison ivy, oak, and sumac dermatitis?
- What is the prognosis (outlook) for poison ivy, oak, and sumac dermatitis?
- How can contact with poison ivy, oak, and sumac be prevented?
- What should people do if they are exposed to a poisonous plant?
- Find a local Dermatologist in your town
Poison ivy, oak, and sumac facts
- Many people are susceptible to the rashes of poison ivy, oak, and sumac.
- The sap oil, called urushiol, causes the skin rash.
- Poison ivy is not contagious.
- Washing the oily sap from the skin with water and soap immediately can help prevent the rash.
- Avoiding direct contact with the plants can prevent the rash.
What causes the rash? How do I identify poison ivy, oak, and sumac?
Poison ivy is a common cause of contact dermatitis, an allergic reaction to something that comes in direct contact with the skin. Allergic contact dermatitis as a response to plants is sometimes referred to as allergic phytodermatitis. This condition can be quite unpleasant but does not typically pose serious health risks. Prevention of the condition is best.
Poison ivy, oak and sumac are among the plants that produce a resin called an urushiol that can cause an allergic rash. These plants belong to the plant genus known as Toxicodendron. The plants are found in different geographical distributions and are present throughout the U.S. except for desert areas, higher elevations (above 4,000 feet), Alaska, and Hawaii. (Poison ivy is most common in the eastern U.S. and poison oak and sumac in the Southeast.) The signs and symptoms produced by each of these plants cannot be distinguished from one another by their appearance. In addition, the same urushiols are also found in the mango, cashew, and ginkgo trees. In the case of mangos, peeling the fruit prevents dermatitis. People who press the whole fruit, including the rind, against their skin can develop a severe reaction around the mouth. Those downwind from burning vegetation containing one of the offending plants can also develop widespread allergic reactions.
Identifying poison ivy, oak, or sumac
Both poison ivy and poison oak have three leaflets, while poison sumac more commonly displays leaflets of five, seven, or more that angle upward toward the top of the stem. Although it is often recommended that people learn to recognize the poison ivy plant ("Leaves of three, leave them be"), in practice, this can be difficult, since poison ivy and its relatives are often mixed in with other vegetation and not noticed until after the rash has begun. The leaves are shiny on their surface.
More than half the population can react to the poison ivy resin if they are exposed to it. Keeping the skin covered in situations in which exposure is hard to avoid is the best way to prevent the problem.
Picture of Poison Ivy Plant and Poison Ivy Skin Rash
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