Poison Ivy, Sumac, and Oak

What is poison ivy, sumac, or oak?

"Poisoning" from plants such as poison ivy, poison sumac, and poison oak is an allergic reaction that happens when your skin touches these plants. Contact with the oil in these plants causes most people to have a rash, blisters, and itching. This contact usually happens in the spring and summer.

Poison ivy and poison oak have three leaflets on each stem and grow as a vine or bush. Poison sumac has opposing rows of 7 to 13 leaflets on each stem, with one leaflet at the end of the stem. It grows as a shrub or tree usually in damp, cool, marshy places. The poisonous oil is in the sap of these plants and oozes from any cut or crushed part of the plant, including the roots, stems, and leaves.

How does the allergic reaction occur?

The allergic reaction happens after touching one of these plants. A reaction can also occur after contact with anything that carries the oil from the plants, including clothes, tools, animal fur, or ashes and smoke from burning plants.

What are the symptoms?

The symptoms of an allergic reaction to poison ivy, sumac, or oak include the following, from least serious to most serious:

itching, often intense
red blotches that may be raised or flat
blisters, which may show up in rows
fever
headache
swelling of your throat and eyes
overall swelling of your body
general feeling of discomfort
stomach cramps, nausea, vomiting, diarrhea.

Usually the rash is first noticed 1 to 2 days after contact. How bad the rash will be depends on the thickness of your skin, how allergic you are to the plant, and how much contact you had with the plant's oil.

How is it diagnosed?

Your health care provider will ask about where you have been recently and will examine the rash.

How is it treated?

To treat contact with poison ivy, sumac, or oak, follow these steps:

As soon as possible, wash all exposed skin with strong soap and water (or just water) to remove the plant's oils.
Remove your clothes and shoes. Wash your clothes in detergent and water.
Soak some cloth in aluminum acetate solution (Burrow's solution) and put the cloth on the rash. Then put calamine lotion or ointment on your skin to reduce the redness, ease the itching, and help dry up the blisters. Soaking in a lukewarm bath with cornstarch (1/2 cup) or colloidal oatmeal added may help ease the itching. DO NOT put lotion containing antihistamine on your skin.
Cover any oozing blisters with a clean gauze bandage soaked in a baking soda and water solution.

Once the oil is washed off the skin, the rash cannot be spread by scratching itchy skin or from oozing blisters. However, scratching may lead to infection of the open sores.

If the rash spreads to your face, mouth, eyes, or genitals, or if you have a fever, headache, extreme redness, pus, or other severe symptoms, see your health care provider. He or she will recommend one or more of the following:

putting a corticosteroid ointment or cream on the affected areas 2 to 3 times a day, gradually reducing to once a day
taking oral corticosteroids such as prednisone
taking oral antibiotics or using an antibiotic cream if the rash becomes infected.

Because these are all potent drugs, ask your health care provider about any possible side effects or interactions with other drugs you may be taking.

How long will the effects last?

The rash usually takes 1 to 3 weeks to heal.

How can I take care of myself?

Follow the steps outlined above to treat your rash. In addition, keep the affected skin clean and dry. Keep your fingernails well trimmed and clean. Try not to scratch your skin to avoid an infection.

See your health care provider if you develop severe symptoms. See your provider right away if your throat starts to swell.

What can I do to help prevent a reaction to poison ivy, sumac, or oak?

Know what the plants look like and where they grow so you can avoid them.
Wear long-sleeved shirts and long pants if you are going to be in an area where these plants grow.
As soon as possible, preferably within 5 to 10 minutes of contact with the plant, rinse exposed skin thoroughly with soap and water (or just water).
Be sure to clean under your fingernails.
Wash clothes in hot water and detergent to remove any oil that may be on them. Also clean shoes, tools, camping or fishing gear, or anything else that has been in contact with the plants. Wear gloves when you do the washing and cleaning and then throw the gloves away.
Give any outdoor pets a bath if you think they have had contact with the plants. Wear gloves and avoid contact with their fur while bathing them.

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

HIA File ALL3112F.HTM Release 9.0/2006