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Poison Oak, Ivy, and Sumac: Plants That Make Us Itch

Liz has always loved camping; her dad was an avid outdoorsman who taught her many skills that are also adaptable to disaster preparedness.

No Warning Labels!

Mother Nature has provided an astounding array of plants. Some are purely beautiful, some are useful, some are medicinal, while still others carry a hidden menace. This includes plants with hidden sneaky thorns or stickers that are not immediately visible from any distance, plants that are poisonous if ingested, and plants that cause rashes if touched.

The rash-producers (the "itchy-poison" group) includes:

  • Poison Ivy (Toxicodendron radicans)
  • Poison Oak (Toxicodendron diversilobum)
  • Poison Sumac (Toxicodendron vernix).

Since Mother Nature has not provided warning labels of the sort required by the government on products which may cause harm if misused, it is up to us to learn to identify these plants by their appearance alone.

Poison Oak can crawl all over the place, on the ground or up trees, fences and walls

Poison Oak can crawl all over the place, on the ground or up trees, fences and walls

Sneak Attacks

The common saying, "leaflets three, let it be," is intended to warn us away from these plants. However, many plants have 3 leaves. It is the particular arrangement of the leaves that is the clue. Do not be fooled into thinking it is only the leaves that have this effect. The irritating oil, Urushiol (Ur-roo´-she-all) by name, is found in all parts of the plant: leaves, stems and roots!

It is not always easy to spot the malicious specimens, for many like to hide in amongst other plants, ready to ambush unsuspecting passersby. Blackberry brambles, for instance, are a favorite hiding place for poison oak. We had some kids at Girl Scout camp discover this the hard way one year.

There are certain "natural" habitats for these pests, but they can, in fact, appear anywhere, due to transport by animals via seeds in their droppings. Annoyingly enough, most animals are immune to the effects, possibly because their skin is protected by fur or feathers, so that the oils responsible for the irritation and inflammation never actually touch their skin.

On the other hand, deer will eat the stuff, and not be harmed!

In the photo below, notice the similarity in leaf structure between the blackberry and the poison oak. It explains why the young Scouts did not notice the poison oak. However, there are three significant differences. 1) Poison oak leaves are glossy, where the blackberry leaves are dull. 2) Blackberry plants have thorns; poison oak does not. 3) Poison oak leaves have a much more rounded appearance to the leaf lobes; the blackberry leaf has a ragged, or 'toothed' appearance.

Blackberry Vine

Notice the similarity in the leaf structure between blackberry plants and poison oak.

Notice the similarity in the leaf structure between blackberry plants and poison oak.

Side-by-Side Comparison Poison Oak, Ivy, and Sumac


The Role of Pets

Wild animals who run through any of these "poison" plants are not our concern, however. It becomes a problem if you have let your dog or cat out loose, and they have run through the stuff. They are not going to come home and tell you that they found a wonderful patch of poison oak or ivy in which to romp--oh, no!

They will, however, have brought the oils to you on their fur, and when you pet them, you are transferring the noxious element to yourself. Whatever body part you next touch prior to washing your hands will be contaminated with the second-hand oil, which retains full potency! (And yes, you can do it unconsciously--such as blocking a sneeze, or having an itch anywhere.) If you have grabbed and hugged your pet--you are really in for it!

Best bet: keep your dog in your yard or on a leash. The same goes for cats. Yes, cats can be trained to walk on a leash and harness! (Though they are safest from all dangers kept exclusively indoors.)

Leaflets three, let it be!

— Old Folk Wisdom Saying

Folklore Can Hurt You!

Be wary of trying folklore remedies or preventions. This is something my own mother learned the hard way. When she was a child growing up in Massachusetts, where it is Poison Ivy, not Poison Oak that is the problem plant, she and a friend read about a supposed prevention or immunity boost used by the Native American tribes of old.

Apparently, they would find a good patch of the stuff, grab handfuls, and rub it all over themselves. The girls decided this was a wonderful idea--how great would it be to romp all through the woods with never a worry about getting Poison Ivy? They found some in a small patch of woods near their homes, and proceeded to put this ancient "wisdom" into practice.

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Within two days, they both had bad cases of Poison Ivy, my mother's much more severe than that of her friend. She was so covered in rash that even her eyes were swollen shut, and she missed a week of school! The resulting blisters opened up and were oozing, so the rash spread.

Back then, there was no Benadryl or similar antihistamine-based creams and ointments that we have now, so her mother swabbed her down with the old standby of the day, Calamine lotion, several times a day. I imagine she looked like a piece of fluffy cotton candy!

Did It Work?

No. It had quite the opposite effect! Every single year thereafter, until she moved away from the East Coast, she did not even have to go near the stuff--it would find her!

Droplets of the oil borne on the wind, or in smoke from some farmer burning it off his land, and she'd be down with a brand-new case.

Moral of the story: do your research before you try folklore "medicine."

A Rash for All Seasons

Do not think that the plant is dead and harmless in the winter. Even naked stems in the snow still pose the threat. So, we must learn to identify the plant in all seasons.

In spring and summer, it is green-leaved; in fall, it turns beautiful shades of yellow, orange and red, just like many other Fall-foliage colors. In harsh winter climates, it loses its leaves altogether.

In areas with milder winters, it may or may not lose its leaves, but retain the Fall colors until Spring. It retains its full potency, regardless.

Poison oak climbing a tree

Poison oak climbing a tree


Uh-oh! You Got It Anyway! Now What?

Sometimes, in spite of the disastrous results experienced by my mother, the oldest remedies work the best. The best treatment option is still old-fashioned Fels-Naptha bar soap. Keep a bar always in your camping and picnic gear. It is easily stored tied into an old nylon stocking, and then in a plastic bag.

Use it to wash your hands and face, and any other skin that was exposed to the plant. Then, you can shave some off to put in a bucket to pre-wash the affected clothing. (Use rubber gloves, so you don't get it anywhere else before the soap has neutralized the irritant.)

In order of importance, once you've discovered your mistake:

  1. Remove all contaminated clothing, and put it into a plastic bag so it doesn't contact anything else.
  2. WASH the affected area(s) with COLD water and the Fels soap.
  3. Dry gently, without scrubbing
  4. Hope against hope that you did not rub your eyes or touch your face before you discovered that you came into contact

If you failed to notice soon enough, and it came home with you and you've got the rash, here are your next steps to take:

  1. Take a dose of an antihistamine allergy medication
  2. Apply topical anti-itch products to affected areas
  3. Avoid scratching the blisters, as you are liable to cause scars

Poison Ivy Rash

Poison Ivy rash is very nasty-looking

Poison Ivy rash is very nasty-looking

Serious Side Effects

Getting a case of rash from any of these plants is not fun, but sometimes, it can be very serious. If you have accidentally gotten it into your eyes, medical attention is mandatory.

Likewise, if you have been in an area where the plant may have been burned, whether in an agricultural burn pile, or the wind coming off a forest fire, it is possible to inhale the irritating oils in the smoke. This can cause pneumonia and other serious breathing issues which can require hospitalization.

Some people are lucky, and seem to be naturally immune; others manage to develop an immunity. Still other unfortunates are unaffected for years, and then one fine day, they come down with the world's worst case of itching rash. For them, there was probably a 'critical mass' cumulative effect over years of exposure. It is somewhat akin to the veteran sea captain who suddenly becomes subject to getting seasick.

An Ounce of Prevention...

Now that you know what's lurking in the woods, you can go exploring without getting into these noxious plants. Keep your eyes open, and if you're hiking, stay on the trails. Park maintenance workers typically keep the trail itself clear, but step off the path by only a foot, and you may well be stepping into a peck of itchy trouble.

The best prevention, if you know there may be any of these tricksters lurking in similar foliage, is to wear long pants and long-sleeved tops. This will at least prevent direct skin contact, and if you think you were in any of the stuff, you can don disposable rubber gloves to remove your outer clothing, taking care it does not turn inside-out and touch your skin. Wash clothes as soon as possible, but transport them home in a plastic bag, so they don't contaminate any of your other clothing.

If it was a day trip, and no overnight change of clothes is available, then find (best to plan ahead and have with you) a large lawn and leaf plastic bag or old blanket to put over the seat and backrest in your car as you drive home.

Have fun on your outings, and bring back pictures of all your fun, and none of any itchy blistery rashes!

Poison Oak close up

Poison Oak close up

Poison Oak as a creeping 'ground cover'

Poison Oak as a creeping 'ground cover'

© 2012 Liz Elias


Liz Elias (author) from Oakley, CA on June 11, 2012:

Hi, Dolores--

Thanks for adding that additional important tip about long pants and socks! I'm glad you found the article useful, and thanks for the vote!

Dolores Monet from East Coast, United States on June 11, 2012:

I think almost everything looks like poison ivy! After spending a lot of time in the woods, ever since childhood, you'd think I'd recognize the nasty plant. So, if I go in or near a woods, I wear long pants and socks. Though my husband once picked up a nasty case weeding a teeny garden in the city. Voted up for the warnings and pictures!

Liz Elias (author) from Oakley, CA on June 09, 2012:

Hello, watergeek,

Oh, my goodness, it sounds like you had a horrible first experience with poison oak! That sounds really awful. It seems that you lucked out, and did get an immunity, unlike my mom's sorry tale.

Thanks very much for stopping by and sharing your story.

Susette Horspool from Pasadena CA on June 09, 2012:

So my first time was trimming blackberry bushes on the hill behind my house in Oregon. Oh lordie! Did I ever get it! I didn't know what poison oak looked like then, but I sure found out. My arms and my face swelled up and my eyes swelled shut. And itching!! if got irritated for any reason, it would get worse. I had to really train myself to stay calm.

The other weekend I went with a bunch of people hiking in a California canyon. There was poison oak all over the place! We even walked through the middle of fields of it (narrow path). Not a problem. I had a tiny 3-blister rash on my arm afterward and that was it.

Liz Elias (author) from Oakley, CA on June 09, 2012:

Hello, shiningirisheyes--Thank you; I'm glad you found the article to be informative. And no, creepy critters are not fun, either. (Another one of my hubs deals with those...) Your comment is appreciated.

Shining Irish Eyes from Upstate, New York on June 09, 2012:

Informative hub. I deal with many of these nasty plants in my neck of the woods. They are on my list of pesky things along with ticks.

Liz Elias (author) from Oakley, CA on June 09, 2012:

@ unknown spy--Thanks very much for the compliment. I'm happy you enjoyed the article. Now you know what it looks like, so you can avoid it if you do find any. ;-)

@ WannaB Writer--Good that you know what it looks like so you can steer clear. You raise an excellent point about the possibility of dead leaves mixed in with others. If there is poison oak near where you live, you might be well-advised to leave your shoes outside until you can get gloves & scrub the bottoms, so you don't track the oils into the house!

Barbara Radisavljevic from Templeton, CA on June 09, 2012:

So far I've never gotten a case of poison oak, even though I see it on a daily basis almost everywhere I go. I just don't touch it. What's tricky is walking down an oak-lined path in spring where the poison oak is all around and climbing on the trees. It's really hard to know if any of the leaves you might be stepping on are deal poison oak leaves mixed with the dead oak leaves that have blown onto the path.

DragonBallSuper on June 08, 2012:

Wow! great hub! though i've never seen poison oak before :)


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