Poison Ivy, Poison Oak and Poison Sumac

Pamela Egan Practical Practitioner


By: Pamela Egan, FNP-C CDE



Poison Ivy, Poison Oak and Poison Sumac




Leaves of three, let them be. Berries white, run in fright.

Most people do not readily recognize poison ivy, poison oak, or poison sumac in order to be able to avoid these plants. Louisiana is blessed with forests full of all three.

Poison Ivy grows as a climbing vine in most areas, its smooth leaves grow in leaflets of three.

Poison Oak grows as a vine or shrub. It has leaflets of three leaves which are more compact and have a rougher surface than poison ivy.

Poison Sumac grows in wet or swampy areas. Leaflets terminate in three but have side leaves as well.

When you realize that you have come into contact with these plants, immediate action is required to rid the skin of the oily substance which causes the rash.

Thorough washing using soap and water is essential, and liquid dish detergent may enhance removal. Begin cleansing the area as soon as possible.

Washing may not remove all of the oily substance, but removal of most of it can reduce the severity of a subsequent rash.

After washing, swabbing the affected area with rubbing alcohol may further help eliminate the oily substance.

Clothing which may have come into contact with the plants should also be thoroughly washed. The substance may remain on unwashed clothing or other items for days or weeks and contact with the skin can result in a rash.

Also, wash any garden tools, camping equipment, or similar objects which may have come in contact with these plants in order to prevent future contamination of the skin.

The skin rash caused by exposure to poison ivy and similar plants is referred to as contact dermatitis. It is a delayed allergic reaction to an oily substance present in these plants called urushiol. This substance is found in the plants’ leaves, stems, berries, and roots.

When a sensitive individual comes into contact with any of the parts of these plants, urushiol can be transferred to the skin.

A rash may not appear for several days after the exposure. This rash is usually accompanied by intense, continuous itching and is often described by patients as being nearly unbearable.

How widespread the rash becomes depends on the body area directly exposed to urushiol. The substance is often picked up on the hands or clothing and then transferred to other areas of the body. Urushiol may also become airborne in smoke from the burning of these plants and exposure to this smoke can result in a substantial allergic response.

The contact dermatitis caused by poison ivy and similar plants is not contagious. Contact with the rash or skin eruptions does not cause the disease to be transferred to another individual or to another area of the body. However, a person with the oily urushiol on their skin or clothing may indeed transfer this substance to another individual and a rash may result. Pets which have come in contact with these plants may also be a potential source of contamination.

The treatment of contact dermatitis focuses on:

  1. Relieving the intense itching

  2. Drying the rash

  3. Soothing the allergic reaction, while the disease runs its normal 10 to 14 day course and the symptoms dissipate.

Cool, tap water compresses applied to the affected areas may help relieve itching. An astringent added to this solution may help relieve the itching as well as dry the rash.

A lukewarm oatmeal bath may also be beneficial. Over the counter products to prepare this bath are available at you pharmacy.

Hot baths may superficially seem to reduce itching, but may actually inflame the rash, result in intensified itching, and hence should be avoided.

After using soaks or bathing, calamine lotion applied directly to the affected areas may continue to help relieve the itching and dry the rash.

Cortisone creams or lotions may reduce the itching, although these do not facilitate drying. Some oral antihistamines may also reduce the itching sensation, and those which tend to cause drowsiness may help you sleep.

The relief received from these various therapeutic approaches may vary widely, and one may need to try several of these in order to determine which works best. When deemed appropriate, your healthcare provider may prescribe a steroid medication which can provide more rapid relief of symptoms.

This article was originally published May 27, 2003 in The St. Tammany News.


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