Poison Oak: Identification and Treatment

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

By Samantha Caveny
June 24, 2019

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

  • 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. 
  • 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!

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!



Reader Comments

Leave a Comment


When burning brush or yard debris - please be aware that the smoke from poison oak or poison ivy, if breathed in, can cause serious lung irritation.

- Also, pets who have been playing outside can get urushiol on their fur. It won't affect the pet - but it can be transferred to you when you pet or rub the animal or they rub against you.

- The urushiol from dead poison ivy / oak plants and vines can remain potent for years.

- There is a good video on YouTube that many may find helpful - look for "How to never have a serious poison ivy rash again"

Burning poison ivy

I've heard that poison ivy smoke can cause you to choke and can be fatal.

Poison ivy or oak on equipment

Urushiol from poison ivy or oak will adhere to equipment as well. Years ago a buddy & I went rock climbing. Shirtless, we both slung coiled rope over our shoulders which unbeknownst to us had been previously in contact with PI or PO. Needless to say, we both had a nice striped rash across our chests, shoulders, and backs where the rope had rested. Don't forget to clean equipment as well after being in the woods (walking sticks, boots, etc).


Tecnu!!!! Go to your local pharmacy and ask for Tecnu, works like a charm to wash it off if you think it’s gotten on you. I keep a bottle handy at my place and in my truck year round and it does work! Another tip I’ve found is to spray yourself with Cedarcide (it’s cedar oil) which keeps everything from ticks to spiders off you when you’re in the woods. Since cedar is another oil, it creates a barrier and prevents the ivy oil from absorbing into your skin and it’s a natural bug alternative to chemicals on your skin. Trust me, I’m highly allergic to the ivy and I live in bug-ville. Both items work.

Tecnu really works!

I've been a firm believer in Tecnu since stumbling upon it in a drugstore decades ago. I overnighted a bottle to my dad when he got into some poison ivy or oak. He had gone to his doctor and gotten a prescription cream to put on, but it wasn't helping. He performed an experiment, using the Tecnu on one side of his body and the prescription cream on the other. When he went back to the doctor, the Tecnu side was much improved and did not itch, while the prescription cream side still itched and had a bad rash. After showing the doctor his results, he switched to Tecnu exclusively and got rid of the rest of his rash. I keep a bottle next to my bathroom sink during the growing season and use it if I even think I might have come close to any poison ivy. It really does work.

Poison Oak treatment

I get poison oak and ivy but have found this to be an effective treatment if I miss a spot when washing up after exposure or didn't notice touching it.
Take a branch of manzanita (Arctostaphylos) (leave flowers berries and all). Cut it up so that it lays flat in a pan and cover it with water. Put it to simmer for half an hour. Let it cool and dab this liquid onto the rash several times a day until the rash is completely gone.
For me the itching goes away the first day and the rash is gone by the 2nd or 3rd day. Without this treatment the rash lasts 3 to 4 weeks.

Here's the deal, some people

Here's the deal, some people get a reaction to Poison Oak, some do not. I work on a trail crew in Northern California. Of the crew, 7 out of 8 of us get a reaction from the plant. We are in the woods every day and the 7 of us that get reactions (including myself) always have a small rash somewhere on our skin. Our bodies have not built an immunity after years of exposure. The best thing you can do is to not come in contact with the plant. If you do, think that it is like coming into contact with grease and how easily it can spread from your clothing to your skin. My most recent bad reaction was from a clean shirt that was in P.O. 2 months ago which I hesitantly thought was safe to wear. That's my 2 cents.

Poison Ivy & Poison Oak

When I was 12, both of my Grandfather's who were avid gardeners and outdoorsmen, told me that if I spent a lot of time in the woods I'd never have a reaction to poison ivy or poison oak because I'd build up an immunity to them.
They must have been right because I've spent a lot of time in the woods in a lot of different states since then, I've never had a reaction to either poison ivy or poison oak, and I'll be 65 later this month.

poison ivy

My mom grew up roaming in the hills of Tennessee and never had a reaction until she was over 60 years old. She came in contact with poison ivy while cleaning out a fence line around her house. Don't think you're immune to the stuff - allergic reactions could crop up at any time.

Poison Ivy

My mother, who was sorely afflicted with hay fever anyway, unwittingly ran through a patch of poison ivy when she was a teenager. She was on a track that had been cleared, several other kids ran the same track and had no adverse effects, my mother ended up in the hospital, with a tube in her airway to keep it from swelling completely shut. They said she must have breathed in some dust that had the urushiol in it. Her sensitivity to allergens (hay fever) just served to make it worse.

When I was younger never

When I was younger never bothered me. I fished and hunted all over Texas hiked in it up to my neck never got it a couple years back decades later got it 2 times all over was miserable. Went to the Dr all they want to do is give you an injection with steroids. The best secret Cheap winter green alcohol 70% (1) Bottle of campho phenique liquid (1) bottle of 100 hundred count generic aspirins. Remove a little of the Alcohol and add back to the bottle later> Crush up all the aspirins in to an almost powder like state pour into the Alcohol bottle shake a few times repeat with the campho phenique liquid pour it into the bottle as well shake a few more times. Get a clean cotton wash rag pour some on it on pat all around the infected areas keep doing over and over and in about 3 days it will be gone.

itch relief

I've never reacted to uresol, when I was a kid in boy scouts I'd set my tent right in the middle of poison ivy patches to keep the others from trying to get in on my dinner (I cooked, while they were eating foil burgers and hot dogs I'd be having fried chicken, mashed potatoes and gravy, etc.)
That said, my mom and now my girlfriend are both highly allergic to it and if they will wash with SOAP (not detergent) ie: Ivory or Fells and cool water right after exposure they won't get any reaction. DO NOT use warm/hot water as this will open pores and allow the oil to get in them and you'll wish you could peel your skin off. If you wait until the reaction has begun, rubbing a wet bar of soap on the rash and letting it dry will relieve the symptoms and dry the rash. This will also work as a preventative, just rub any exposed skin with the wet soap bar before going out, let it dry on your skin and it will form a barrier on the skin that can be easily washed off after you get back in from the woods.

Got it without going near it!

My husband has always been a heavy construction worker. One time, the crew was working in a creek bed to shore up some sliding areas below a bridge. After about a week, I broke out with poison oak, and it got so bad that I ended up in the emergency room completely covered in it, and with it starting to go inside of my eyes, mouth, and other body openings! It was awful. Turned out I had been exposed to it by my husband's work clothes when I did the laundry! Needless to say, I stay FAR AWAY from it now!

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!