Poison Ivy, Oack and Sumac

 In Health Library

A Rash of Information about Identification, Treatment & Prevention

What is it?

Poison ivy, oak and sumac belong to a family of plants that produce one of the most common allergic reactions in the United States. Experts estimate that up to 70 percent of the population is allergic to urushiol (you-roo-shee-ol), the oil found in the sap of these plants. The reaction, known as “urushiol-induced allergic contact dermatitis, ” occurs when urushiol attaches itself to the skin after a person’s direct or indirect exposure to the oil. Symptoms like rashes, oozing blisters, itching and swelling are the body’s way of telling you that you are having an allergic reaction.

An example of a poison ivy allergic reaction. Wiping contaminated hands on the neck produced the swollen, streaky appearance.

An example of an allergic reaction to urushiol. Direct contact produced redness, swelling, blistering and rash.

What does it look like?


Poison Ivy

The most common of the three plants, is characterized by three or five serrated- edge, pointed leaflets. These leaves assume bright colors in the fall, turning yellow then red.


Poison Oak

Has three oak-like leaves and grows as a low shrub in the eastern U .S. and as both low and high shrubs in the western U.S., where it is most prevalent. Poison oak produces whitish flowers from August to November that dry but may remain on the plant for many months.


Poison Sumac

Has seven to 13 staggered leaflets with one on the tip of the plant. Mainly found in the eastern U.S., poison sumac grows in peat bogs and swamps as a shrub or a small tree. The large allergen-containing fruit is red and grows between the leaf and the branch.

Questions & Answers

How do these plants cause allergic reactions?

Urushiol, the allergen found in these plants, attaches to the skin within five minutes to two hours after exposure. This event triggers an allergic response, whereby the body’s immune system attacks the skin containing the urushiol. Reactions result from direct contact with broken leaves or stems of the plant; indirect contact by touching something that has urushiol on it (like a family pet or garden tool); or through airborne exposure to burning plants.

What are the signs and symptoms?

An allergic reaction to poison ivy (oak or sumac) is quite intense and far more common than any other cause of an allergic skin reaction. Signs and symptoms include redness, swelling, warmth, blistering, tenderness and of course, itching.

What are the treatment options?

Over-the-counter remedies like calamine lotion or hydrocortisone may alleviate the itch. Your physician also may prescribe steroids or more severe cases to reduce inflammation and stop itching. However, side effects of excessive use may include thinning of the skin, acne and discoloration. Oral steroids also carry health risks, especially for young children.

Zanfel™ Poison Ivy Wash provides a valuable alternative to drug therapies for mild to moderate cases. Sold in the First Aid section of pharmacies. Zanfel is clinically shown to remove urushiol after breakout and relieve itching within seconds of use.

Medical experts caution against the use of topical creams containing anesthetics (benzocaine) or antihistamines (diphenhydramine). because these agents are known sensitizers that can actually worsen the rash through the body’s allergic response to these drugs. Further, there is doubt of their effectiveness.

What to do if you’ve been exposed to poison ivy, oak or sumac:

1. Cleanse: Immediately cleanse the area with plain soap and water, paying special attention to the

   palms of your hands. Since this outer layer of skin is thicker, urushiol does not penetrate the area

   and can be carried on the palms for hours. Urushiol will bind to the skin within five minutes to two

   hours after exposure. After binding, plain soap and water are no longer effective at removing


2. Decontaminate: Remove and wash all clothing, shoes and shoelaces that may have come in

    contact with the oil.

3. elieve: If signs or symptoms appear, use Zanfel, the only product clinically shown to remove

    urushiol from the skin after breakout and relieve itching. Removing urushiol is the most important

    step in eliminating the reaction. Other common remedies, such as calamine lotion, may produce

    mild and temporary relief of the itch but will not remove the oil.

4. Don’t scratch! Scratching may cause infection because it allows bacteria from dirt on the hands to

    enter the skin. Excessive scratching may also cause scarring.

5. See your family physician: Be sure to consult your family physician if symptoms worsen and/or the

    rash spreads to the mouth, eyes or genitals. Severe reactions may require further treatment.

How to prevent a scratchy situation:

1. Know what to look for and educate your family. Prevention is the best form of protection from

   poison ivy, oak and sumac reactions. Before you head outside, make sure your family knows how

   to identify these plants so they can avoid them.

2. Wear protective clothing. Shielding clothing, including long pants, long- sleeved shirts, hats and

    gloves, can help protect you from exposure.

3. Wash outdoor items frequently. Be sure to wash all clothing, shoes, tools or pets that may have

    been exposed.

4. Do not burn any suspicious plants. Burning the problematic plant and inhaling its smoke can cause

    a systemic reaction, which can be deadly. Also, do not burn items of clothing or rags that may

    have been exposed.

5. Stop the symptoms before they start. If you know you’ve been exposed to poison ivy, cleanse the

    area immediately with plain soap and water to remove urushiol before it has a chance to bind to

    the skin

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