Poison Oak: Identification and Treatment

What's the Difference Between Poison Oak and Poison Ivy?

By Samantha Caveny
June 24, 2019
poison-oak-identify-treat

Poison oak can be a harmful plant if you touch it, as its urushiol oil will cause a nasty rash.

California State University Channel Islands

“Leaves of three, let it be!” “Hairy vine, no friend of mine!” Learn how to spot poison oak, tell the difference between poison oak and poison ivy, and treat a poison oak rash. 

What is the Difference Between Poison Oak and Poison Ivy?

Poison oak is a relative of poison ivy. There are many similarities:

  • Both plants contain the same toxic resin, urushiol in all parts of the plant (toxic to humans but harmless to animals). 
  • Both plants have three leaflets, white flowers in spring, and can grow as a vine or a shrub.
  • Leaflets can range in size from the length of your thumb to the length of your hand.
  • Middle leaflet has a notably longer stem than the two side leaflets, though more obvious in poison ivy than poison oak.
  • Depending on the season, leaf color can range from green to orange and even a dark purplish-red.

But they are indeed different plants. In North America, there are two species of poison oak: Atlantic (Eastern) and Pacific (Western). 

Poison ivy (left) vs. poison oak (right)
Poison ivy (left) vs. poison oak (right)

How to Identify Poison Oak

  • Atlantic poison oak is a low-growing, upright shrub. It can grow to be about 3 feet tall, sometimes giving it the appearance of a vine. Pacific poison oak can grow either as a shrub or a vine, causing it to be even more readily confused with poison ivy.
  • Leaf shape resembles an oak leaf (hence the name, poison oak), but it’s not a member of the oak family.
  • Leaflets are duller green than poison ivy and usually more distinctly lobed or toothed.
  • Leaflets have hairs on both sides, unlike poison ivy.
  • Poison oak tends to grow at elevations between sea level and 5,000 feet.
  • While the fruit of poison ivy is the color of pearls, poison oak fruit (called “drupes”) has a tan color.

At the end of the day, just remember: Leaves of three, let it be. In other words, if you see a plant with clusters of three leaves, don’t touch it!

poison-oak-fruit-identify.jpgpoison-oak-cluster_0.jpg
Left: Poison Oak can be red in the fall, and its berries are tan when mature. Right: Poison Oak leaflets showing coloration.

Poison Oak Symptoms

Symptoms of poison oak include itchy red rashes that can resemble burns, swelling, and even blistering.

Symptoms can take 24-48 hours or even up to a week to show up, particularly if its your first exposure! 

Poison oak, like poison ivy, contains urushiol. This oily substance is what causes a poison oak rash, and it can be almost impossible to avoid. Upon contact with your body, urushiol immediately forms a chemical bond to the skin and causes an almost unstoppable allergic reaction. Urushiol will stay on clothes, pets, or other materials for months, and its potency lasts. This means that you could even get poison oak without going anywhere near it. 

The urushiol resin can cause harsher reactions for those who have been exposed to it before. Sensitivity to urushiol might decrease if you do not come into contact with it until later in life. Only about 15 percent of people are resistant to urushiol, so don’t feel safe around poison oak unless you are absolutely sure you are resistant. You also may become sensitive with repeated exposure, so your resistance might be short-lived.

Danger: Smoke inhalation from burning poison oak can send you straight to the emergency room. Avoid burning this plant (and poison ivy)!

Poison Oak Treatment

Your best chance at avoiding a reaction is to treat poison oak within 10 minutes of contact.

Urushiol is not water-soluble! Use strong soaps (like dish soap) and wash with cold water to keep the oils from spreading. Cleanse the area of contact within the first ten minutes, then rinse off with cold water. As urushiol can remain active for years, you’ll want to wash any clothes, items, or furniture that may have come into contact with the invisible oily residue.

If you don’t catch the exposure immediately, treat the resulting itchy rash and blisters topically with calamine lotion, baking soda pastes, aloe vera, and a number of commercial products.  If you don’t mind mixing breakfast and skin care, one tried-and-true remedy for itchy skin is oatmeal.  Since poison oak rash is the same as the poison ivy rash, see more remedies on our poison ivy page. If poison oak is extremely serious, speak to your doctor about a prescription.

Of course, the best remedy is always prevention; study our photos so you can recognize poison oak.

Have you ever had a run-in with poison oak? Tell us about it in the comments below!

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Reader Comments

Leave a Comment

Poison Ivy

I got into poison Ivy while trimming small branches from a small tree eight days ago. I was using a small hand saw. I just did not see it, but where my wrists touched the bark, just passed the glove gauntlet is terrible. I did go after five days and got a steroid shot and prescription Triamcinolone ointment. I am now trying white vinegar and that is soothing as well. Be sure and wash all clothing very well as well as yourself in lukewarm water. It had been 15 years since I got a bad rash. I sure wish I had inspected the area better.

Poison Ivy blisters

Will the poison ivy urushiol spread if you break open the blisters to speed up the drying out? Someone once told me that this doesn't cause spreading. I was also told today that pouring bleach on the punctured blisters helps speed up the drying process.

can poison ivy spread?

The Editors's picture

Hello! We’re sorry to hear you are dealing with poison ivy. The blisters leaking will not spread poison ivy because the fluid in the blisters is not plant oil. If you want to try bleach to relieve the itch and speed healing, combine equal parts water and bleach and dip a cotton ball into the solution. Apply to the affected area. Good luck!

Response to Dadbo

When I was little, my brothers and I would occasionally run into a patch of poison oak while playing outside. My mother treated the area by using cotton balls soaked in hydrogen peroxide and scrubbing the blisters with them. Hurt like you wouldn't believe, but dried up the blisters and stopped the itching. I would not use bleach on your skin, especially on broken skin, like blisters. Bleach is a caustic chemical and could leave you with a nasty, possibly serious, chemical burn.

Poison Oak/Ivy Blisters

I am very allergic and have had it several times to the point of weeping itchy blisters that last for 2+ weeks. Nothing worked well but I found I could dry up the blisters with PORTLAND CEMENT! If you have ever worked with concrete you know how dry your hands get. Pure Portland cement seems to work well at drying up blisters from these cursed plants. Just put apply the dry powder directly to the weeping blister. It seems to help the itch some also, but nothing beats a steroid for curing it quickly. I was always given a 7 day treatment of Prednisol and it reversed the effects quickly. It also gives you an appetite. It would make cardboard taste good so you may gain weight!

Poison Oak

I hear the word poison oak and i'm instantly itching. I have tried a few different remedies. The two that seem to work best for me are CORTIZONE 10 (OTC) or good ole rubbing alcohol. The alcohol actually dries it up quicker. I also try to cover it as much as possible with gauze and tape or something so I don't keep rubbing, itching it and spreading it.

Welcome to the South!

I moved from Colorado to South Carolina and had bought a custom built home with lots of natural area in the back. Little did I know how much poison ivy was lurking in that space. I broke out from head to toe. I spent 4 weeks covered in bruises from scratching! Full on South Carolina summer and I had to wear long pants and tops to hide the bruises and splotches. It took two prescriptions of prednisone and two shots to eventually ease my discomfort. What a welcome to the south!!!

Itching from poisons..and peach tree leaf curl.

#1 I am highly allergic to all. Sumac is very prominent where I live. E.r. would not theme a shot after prednisone. It would shut do wn adrenal glands. Lots of oral benadryl, ice packs are a god sent to stop itching. #2 I used cinnamon on peach tree leaf curl instead of fungicide. Worked great and cured it.

Im in Florida and love

Im in Florida and love yardwork and gardening which has unfortunately confirmed i am not a person that is immune to poison ivy/oak. Ended up on steroids for 3 weeks. My skin is still recovering and i have scarring on arms/face from the exposure. Please folks, make sure u protect urself out there with proper clothing and have dish soap or ivy wash immediately avail just in case. Good luck out there!

Poison Ivy

When I was in my early teens I spent a great deal of time in the summer months fishing with my Grandfather, on one fishing trip we decided to have lunch onshore at a secluded location. I grabbed the limb of a bush to pull us to shore and on that limb was a vine. After I had pulled the boat to shore my Grandfather told me that I had grabbed a limb with poison ivy on it and that I may break out in a rash, but if I spent a lot of time in the woods I wouldn't break out in a rash because I would have built up an immunity to poison ivy. I didn't break out in a rash then and I've spent a lot of time in the woods since, I have never broken out in a rash from any source found in the woods. I guess that despite the naysayers, a person really can develop an immunity to poison ivy and poison oak if they spend a lot of time in the woods.

poison ivy

when exposed to poison ivy we always, as soonas possible, wash the area with Fels Naptha
laundry soap.. it always works I even wash high top boots that have been exposed to the soap

Fels Naptha laundry soap.

Fels Naptha works on poison oak, poison ivy and poison sumac too.. I don't know how it works; however, it works for us...

Poison Ivy

I have been extremely sensitive to Western poison oak; and once was exposed to poison ivy ABOVE 5000' in NM, about 6000' elevation and did suffer a rash....so FYI, it apparently can grow above 5000' !!. Then there's poison sumac as well...any info on that??

Poison oak/ivy

I don't get it either but many members of my family get it really bad. The remedy we use is manzanita leaves. You pick the leaves, boil them until the water turns brown, strain the leaves out, and put the water in the fridge. Once it is cool, dab on the affected area with cotton balls. Even extreme cases are usually cleared up within 24 hours. I don't know why it works but it does. I learned it from my daughter's heart grandmother years ago.

Poison oak/ivy

Great grandmother, not heart, Lol!

I had not heard of Manznaita

I had not heard of Manznaita (Little apple); interesting; thanks; Medicinal use[edit]
Native Americans in Northern California made a tisane from manzanita leaves to treat poison oak rash.[3][4] The leaves contain chemicals with a mildly disinfectant quality, and can be used for mild urinary tract infections.[4][5][6]
Culinary use[edit]
The berries are a good food, as they can be harvested en masse and stored.[4] Once stored and dried, the berries can be ground into a coarse meal.[5] The berries can be eaten ripe (when red) or green for a slightly sour taste. They are good eaten alone, or used as a thickener or sweetener in other dishes.[4] Fresh berries and branch tips can be soaked in water to make a cider. Native Americans used Manzanita leaves as toothbrushes.[7];

Manzanita cures poison oak/ivy rash

Living in NE California, where there is plenty of poison oak. Coworker shared a Native American remedy which she received after horseback riding through an intense patch. So thankful for her share, as within the week, my nurse daughter had been exposed while hiking. We went outside, picked manzanita leaves and boiled to make a tincture. Directions were to apply wet cotton balls or gauze pads on rash and wrap the area with gauze bandage, leaving covered for 24 hours. Amazing! She has very little itching, and when the bandage was remove, the rash area was dry looking and no new blisters formed. I also lived at Forest Service fire stations for several years and watched the guy poor bleach directly on the blistered areas....I prefer the manzanita treatment!

Poison Oak and Ivy

I have never been "allergic" to either one. I can pull it up bare handed and not have any effects. Others just have to get fairly close and they are covered with Calamine lotion the next day. When I was in my 20's I would go White Water Canoeing with some buddies. One guy brought his family and we needed a bigger campsite so we went up the hill and found a bigger one. They put their tents on one side and I sat mine on the other side. On the way home they said "Stay away from me. Your tent was in Poison Ivy and oak". I said "Oh My God. Why didn't you tell me"? And they all laughed. The next day at work Frank and Danny were both covered in Calamine Lotion. When they saw I didn't have any on me, they asked "Didn't you get all that poison Ivy on you? Your tent was set up right next to it." I said I know, but I'm not allergic to it and you're both scratching your selves to death". And I laughed because they like to mess with people and think it's funny when something bad happens to someone instead of helping or informing them about something. I said "Jokes On You". I wasn't gonna say that if YOU get withing 20 feet of it (from the way the wind was blowing) that YOU"D GET EAT UP WITH IT. hahaha So they thought they were gonna laugh at me when I got the last laugh and it was the last time they asked me to go canoeing with them. Talk about MAD. I'd ask them if they found any NEW Poison Ivy or Oak patches and they'd turn red and not from the Ivy or oak. haha

Don't count on it

My dad was able to pull up poison ivy with bare hands with no reaction... right up until the time he wasn't. Consider yourself lucky you don't react but don't count on it always being the case.

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