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  • Got the Itch? More about Poison Ivy, Oak and Sumac

    A rash decision: avoid poison ivy.About 85% of us have allergic reactions to poison ivy, poison oak and poison sumac, which are all members of the Toxicodendron genus. Poison ivy is most common in the eastern United States, poison sumac in uninhabited areas and poison oak in the west.

    Poison Ivy, Oak and Sumac Facts

    • The plants' resin contains the chemical urushiol, which remains present even in dead or decaying plants and in the smoke from burning plants. The smoke can affect not only skin but also nasal passages, throat and lungs.
    • Urushiol is easily transferred from one object to another and even very small amounts of the chemical cause an uncomfortable rash.
    • Garden tools and hoses, clothing and household pets that come in contact with urushiol must be thoroughly cleaned because the chemical is active for at least a year.
    • Contrary to intuition and popular belief, however, scratching the blisters that form on skin does not spread the rash because the blisters themselves do not contain urushiol.


    Prompt use of soap and water is the best prevention of an allergic reaction to urushiol. If it is washed from the skin within five minutes of contact it is unlikely that any rash will appear, but washing after that period of time is beneficial to prevent spreading of the chemical.

    For most people, learning to recognize the plants, wearing clothing that doesn't expose skin and washing thoroughly after possible contact is precaution enough.


    Calamine lotion is still the recommended treatment as a drying agent and to help relieve itch. Cool showers and lukewarm baths to which oatmeal or baking soda is added also provide relief. The rash and itching persist for about ten days. A physician should be consulted if the rash covers more than 20 percent of the body, or if the face or genital area is involved. The doctor may prescribe antihistamines and corticosteroid creams.

    A new topical treatment-bentoquatam, which is available without a prescription-can prevent the rash by forming a barrier on the skin. Applied about 15 minutes before exposure, it is helpful to those who cannot avoid contact (hikers, park rangers, land clearers and others). 

    For more information, call 401-444-7959