Protecting Yourself from Poisonous Plants

| Posted On Jul 29, 2015 | By:

poison ivyHappy summer everyone! With the warmer weather comes a different set of skin health issues than we see during the cooler months. Your skin can be damaged by sunburn, assaulted by flying insects, or, if you enjoy working in the garden, hiking or camping, your skin can come in contact with poisonous plants.

Poison ivy, poison oak and poison sumac are three commonly found plants whose oil, known as urushiol (you-ROO-shee-all), has been known to cause an allergic contact dermatitis (ACD), a type of eczema that is an allergic reaction at the site of exposure. According to the American Academy of Dermatology, 85% of people will develop a rash when they get urushiol on their skin. The reaction can range from a minor rash and itch to a more severe reaction with blistering and swelling.

The best way to avoid getting poison ivy, oak or sumac is to learn how to identify each of these plants. The old saying, “leaves of three, let it be” is a good place to start, although there are species of these plants with more than three leaflets.

Poison Ivy

poison ivy collage

Poison IvyPoison ivy grows as a ground cover, a low shrub or as a vine that climbs up trees. It can be found across most of the United States, and it’s what most of us in the northeast are most familiar with. (Here is a photo of a patch I pass on my usual bicycle loop through my neighborhood.)

The leaves start out solid green, in clusters of three per stem. They can be dull or glossy with pointed tips and the thin, aerial roots give the vines a fuzzy appearance. In the summer, poison ivy plants produce yellow-green flowers that are followed by whitish berries. In the fall, the leaves become yellow and red.

Poison Oak

Poison Oak Collage 2

Poison oak leaves look a lot like regular oak leaves and they usually grow in clusters of three. However, some kinds of poison oak have five, seven or nine leaves per cluster. Poison oak usually grows as a shrub and is most commonly found in the Southeast or the West Coast. It produces clusters of greenish, yellow or white berries.

Poison Sumac

Poison Sumac Collage

This plant likes to grow in swampy locations and typically has seven to 13 leaflets arranged in pairs. The leaves sometimes have black or dark brown spots. In the fall, the leaves turn red, yellow and pinkish. Poison sumac grows into a woody shrub with glossy cream or pale yellow berries.

The urushiol oil in poison ivy, oak, and sumac is present in the leaves, stems, and roots of the plant. You don’t need to touch these plants directly, either, to get the oil on your skin – the oil may be carried on the coats of household pets or on gardening tools and then transferred to you. Once exposed, the oil is immediately absorbed into the body through the skin. After your first exposure, the rash may take a week to develop whereas with subsequent exposures, the rash may develop within 12-72 hours. It may not appear all at once, but it may appear in different areas over several days, leading people to believe the rash is spreading. It is a myth that the rash is spread through the fluid in the blisters: it is only direct contact with the urushiol oil that causes the rash to develop. If the oil is on your skin, the rash can spread to other parts of your body through contact such as scratching or rubbing your skin.

Please note that you should never burn any parts of these plants, as the smoke can carry the urushiol oil into your nose, throat and respiratory system and cause more serious health problems.

If you suspect you have been exposed to poison ivy, oak or sumac, you should wash your skin with soap and warm water as soon as possible and scrub under your nails with a brush. The oil can stick to many surfaces, such as gardening tools, golf clubs, and your pet’s fur, and remain active for more than a year, so be sure to rinse your pet’s fur and wash any tools or objects with warm, soapy water. Contaminated clothing should be washed separately in hot water with detergent, and be sure to rinse your washing machine thoroughly to remove all traces of the oil.

If you do develop symptoms, you can take short lukewarm baths to help soothe the skin. Oatmeal baths may also help relieve the itch. You should avoid scratching the skin or breaking the blisters as this will increase the sensation of itch and the risk of infection.

Cool compresses, hydrocortisone cream or calamine lotion are all treatments you can pick up at your local pharmacy and try safely at home. If the itch is keeping you awake at night, you can try an over-the-counter antihistamine, such as cetirizine or diphenhydramine.

You should seek medical attention if you experience any of the following conditions:

Your doctor may prescribe a topical steroid cream or ointment. These may need to be used for 10-14 days, as that is typically how long you can expect the rash to persist. Oral steroids are prescribed in very severe cases or when your vision is threatened.

If you work outside and are at frequent risk of exposure, ask your doctor or dermatologist about over-the-counter skin products that contain a barrier, such as bentoquatam, that can help protect your skin from urushiol. For everyone else, before you head outside, learn to identify these pesky plants!

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About Glen Blair, NP

Glen Blair has been a nurse practitioner since 1997 and has been employed at Harvard Vanguard Medical Associates for nearly 15 years. He is Program Coordinator for the department of dermatology and is in charge of education and special projects for the nursing staff. He is certified as a Dermatology Nurse Practitioner and sees patients at the Chestnut Hill/West Roxbury and Kenmore practices. He teaches a class on dermatology to nurse practitioners and physician assistants at the University of Massachusetts, Boston, and has published chapters in dermatology for two textbooks as well as articles in the Journal of the Dermatology Nurses Association. He is also an experienced public speaker, having spoken about dermatology issues at a number of national conferences.

Comments

  1. You didn’t mention Zanfel, an OTC treatment that works very fast for relief and clearing up the rash. It is pricey but works so well it is worth every penny!

    Comment by Kathie Lynch Nutting on August 19, 2015 at 12:21 pm
  2. Mangoes are related to poison ivy, and in sensitive people, the sap of their trees, usually found as black spots on the exterior of the fruit, can cause similar reactions. We found out the hard way.

    Comment by Meryl Stowbridge on August 20, 2015 at 10:23 am
  3. Thank you to everyone for the education, especially Glen Blair.

    Comment by J. Fabian Daly on August 21, 2015 at 8:00 am
  4. The old rhyme for identifying poison ivy: “Leaves of three – let it be!” While harmless plants and vines may also have three leaves, being extremely allergic I prefer to err on the side of caution and avoid any plant displaying three-leaf clusters, especially those with glossy leaves.

    Comment by LINDA FERRAZZARA on June 12, 2019 at 12:08 pm
  5. Jewel weed has been very effective for me, although the literature says it is not. I have some in my yard, as well as poison ivy. I am very susceptible, and get blisters soon after contact. By rubbing any part of the jewel plant until is is juicy and then getting the juice on the affected parts, the itch and blisters are stopped. If blisters have already formed, I apply again if the area has been washed. The rash will dry up and go away. The plant does not need to be mature or have flowers on them yet. It is very tender and easily gives up one or two leaves and a little stem. The liquid inside nullifies the poison. I do not know if it could harm another person, who might be sensitive to the antidote, but it works for me. The blisters I had on June 5 are gone now on June 15. Skin is pink, but fading to normal. The itch stops immediately.

    Comment by Judy R. on June 15, 2019 at 5:19 pm

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