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    Poison Ivy, Oak, and Sumac -- the Basics

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    What Are the Symptoms of an Allergic Reaction to These Plants?

    Symptoms, which generally last from one to two weeks, include:

    • Red streaks or patches
    • Itching
    • Rash
    • Swelling
    • Blisters that may "weep" (leak fluid) and later crust over
    • Inflammation and a burning sensation

    Does it matter which plant you're exposed to? Poison ivy, oak, and sumac all fall into the plant species called Toxicodendron, so the allergic reaction to all of these plants has the same name: Toxicodendron dermatitis. There are actually four poisonous plants in this group, since poison oak has both a western and an eastern variation. All four plants contain urushiol, so the skin reaction and treatment are essentially the same.

    How Are Poison Ivy, Oak, and Sumac Rashes Diagnosed?

    Poison ivy, oak, and sumac are generally diagnosed by their common symptoms of a rash, blisters, and itching following activity outside in a forest or field, but if you have any doubt, ask your doctor.

    How Are These Rashes Treated?

    Self-care for a mild rash includes:

    • Wash the area well with mild soap and lukewarm water as soon as possible after contact.
    • Wash all clothes, shoes, socks, tools, pets, and toys that may have become contaminated.
    • Cool compresses may help during the blistering phase.
    • Use a topical corticosteroid cream on the rash as directed by your doctor.
    • Try calamine lotion for the itching, but avoid skin products that contain anesthetics or antihistamines, which can cause their own allergic reaction.
    • To help relieve the itch, try cool showers or a mixture of baking soda and water applied to the area. If sleep is a problem because of the itching, try an over-the-counter antihistamine at night.

    Call your doctor or a dermatologist for:

    • Severe blistering, swelling, and itching
    • Symptoms in sensitive areas such as the eyes, lips, throat, or genitals
    • Fever
    • A rash over large areas of your body
    • A rash lasting longer than a week to 10 days
    • Blisters that become infected with pus

    Get immediate medical help for any difficulty breathing or severe coughing after exposure to burning plants.

    In some cases, an oral steroid or other medication may be needed to relieve severe symptoms.

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