What Is Poison Ivy?

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Poison ivy is a poisonous plant that can cause a skin rash in people who come into contact with the leaves, stem, or roots. This rash, known as contact dermatitis or rhus dermatitis, is actually an allergic reaction to the urushiol oil (which is found in poison ivy, poison oak, and poison sumac plants) produced by the toxic vine. You can also get a poison ivy rash from touching an object (such as a piece of clothing) that has urushiol oil on it. And if you inhale smoke from burning poison ivy, you can experience a reaction in your respiratory passages.

Up to 85% of people will develop this rash if they come into contact with poison ivy. The hallmark poison ivy rash is red, itchy, and swollen, and can also have hives or blisters. You’ll likely know what it is when you see it, although a doctor can tell you if the rash is caused by something else. Most cases of poison ivy rash go away on their own within a couple of weeks. Over-the-counter creams and lotions can help ease the itch. In rare cases, poison ivy can cause more serious complications that may require medical treatment.

RELATED: Is It a Poison Ivy Rash? How to Tell-and How to Treat It

Signs and symptoms of poison ivy rash

About 15% of people are immune to urushiol oil and wouldn’t know if they had a close encounter with a poison ivy plant. The remaining 85% will certainly know it, though perhaps not right away. Evidence that you’ve tangled with poison ivy can take hours or days to appear, depending on how sensitive you are and how much urushiol oil came into contact with your skin.

The main sign of poison ivy is a raised red rash where your skin has touched urushiol oil. The rash may show up in patches, lines, or streaks, which follow where the poison ivy came in contact with your skin. A poison ivy rash is usually also accompanied by swelling, hives, and bumps or blisters that can be either large or small. A few days after they first appear, the blisters can crust and burst, letting loose a clear liquid. The rash may show up on different parts of the body at different times depending on how much oil came in contact with that particular area of the skin.

In more severe cases, poison-ivy rash can spread to your eyes, mouth, or genitals, and blisters may get infected with pus. (If the oil is on your hands, you can spread it to other parts of your body.) If you’ve inhaled urushiol soot, you may have trouble breathing.

Signs and symptoms of poison ivy should usually resolve within a few weeks. Anything longer than this probably needs a doctor’s attention.

Signs and symptoms of poison ivy rash

In milder cases:

  • Raised red rash

  • Swelling

  • Hives

  • Bumps or blisters

  • Itchiness

In more severe cases:

  • Difficulty breathing

  • Eyes swollen shut

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What causes poison ivy rash?

A poison ivy rash is caused by urushiol oil from a poison ivy plant coming into contact with skin. The skin quickly absorbs the oil, which then causes the hallmark rash. Contact with any part of the poison ivy plant—the roots, stem, or leaves—can cause this rash. You can come into contact with urushiol oil either by touching a poison ivy plant directly, or by touching something else that has oil on it, such a gardening tool, a pair of shoes, or a pet’s fur. Urushiol oil doesn’t stay on the skin for very long, but it can stay on objects for years—which means you can easily develop a rash after touching anything that has urushiol oil on it. If the oil is still on your fingers, you can spread the rash to other parts of the body.

You usually cannot get the rash by touching another person who has touched a poison ivy plant because the oil is absorbed into the body so quickly. You also cannot get a rash from liquid out of a burst blister.

In some cases, you can inhale urushiol particles—or get them on your skin—from poison ivy plants that are burning nearby.

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Poison ivy rash pictures

Poison ivy rash can appear anywhere your skin has come into contact with the plant. The rash is red and can be irregularly shaped, or can appear as a line or streak (essentially, the rash will be an imprint of where you brushed against leaves or any other part of the plant). It’s usually accompanied by swelling, hives, and bumps or blisters.

A few days after the rash first appears, the blisters will crust over and burst, releasing a clear liquid.

The rash may appear on different parts of the body at different times depending on whether that area touched a little or a lot of oil. In severe cases, the rash can spread to your eyes, mouth, or genitals. If this happens, contact your doctor.

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Poison ivy plant pictures

Poison ivy grows either as a vine or as a shrub in most parts of the U.S. with the exception of Alaska, Hawaii, and certain areas along the West Coast. The plant is known for the three leaflets that grow on each leaf, a trait that gave rise to the famous warning phrase, “Leaves of three, let them be.

The leaflets can be rounded or have multiple jagged edges. The plants are usually green around a red stem but may also be red, brown, or green with black dots (this is urushiol) depending on what time of year it is and where they’re located. Poison ivy may sport berries—yellowish white, orange, red, or yellowish green depending on the season.

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How is poison ivy rash diagnosed?

Most cases of poison ivy are obvious just by looking at the rash, and if you know that you have come into contact with foliage. The rash will be red, swollen, and itchy and usually has hives and small or large bumps or blisters. The blisters usually last a couple of days before they burst, giving off a clear liquid. Don’t be surprised if the rash looks different on various parts of your body at different times. This is normal and doesn’t necessarily mean the rash is getting worse.

A doctor, particularly a dermatologist, can provide a more definitive diagnosis. He or she can also help you rule out other causes.

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Poison ivy treatment

There is no cure for poison ivy rash. It will usually go away on its own, even if you do nothing. Fortunately, there are treatments to relieve symptoms, the most bothersome of which is itching.

If you develop a rash, don’t scratch it. Instead, try one of many over-the-counter products that are available to tame the itch, such as calamine lotion or hydrocortisone cream. Oral antihistamine pills can also reduce itching and may help you sleep.

If your rash doesn’t show signs of abating after a week or 10 days, contact your doctor. He or she may prescribe a stronger steroid ointment and, if you have signs of an infection (swelling, pain, pus around the rash, or a rash that is warm to the touch), an antibiotic.

Contact your doctor or go the ER if you develop a temperature over 100 degrees, the rash spreads to your genitals, eyes or mouth, you have trouble breathing, your tongue or throat starts swelling, or the rash covers more than a quarter of your body.

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How long does poison ivy rash last?

It’s hard to know how long symptoms from poison ivy will last. It usually depends on how sensitive you are and how much oil got on your skin. A poison ivy rash that lasts one to three weeks is not unusual. The first signs (red, swollen, itchy skin along with blisters) can develop hours or days after first contact with a poison ivy plant. A few days later, the blisters will get crusty and drop off. A poison ivy rash may also show up on different parts of your body at different times depending on how much urushiol oil landed on certain areas. The skin usually absorbs the oil quickly, but it can linger on objects for years. If your rash doesn’t go away in a couple of weeks, contact your doctor.

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Poison ivy rash home remedies

Simple home remedies can help ease itch from a poison ivy rash. Bathing in cool water can be a huge help, as can pressing a damp cloth (make sure it’s cool as well) on the itchy area for 15 or 30 minutes at various times throughout the day. Avoid hot water, as that can worsen the rash. Many people find that soaking in a colloidal oatmeal bath (you can make your own or buy a product at the drug store) also does the trick. Some experts recommend easing blisters with a solution of one or two Dome-Boro tablets (available at most drug stores) dropped in a pint of water.

Poison ivy rash medications

  • Calamine lotion to relieve itch

  • Hydrocortisone cream to relieve itch

  • Oral antihistamines such as Benadryl to relieve itch

  • Antibiotics to heal a bacterial infection around the rash

  • Steroids in more severe cases to reduce swelling, redness, and itching

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Is poison ivy contagious?

You can’t get poison ivy from another person unless the person still has urushiol oil on their skin. This is unlikely, though, since skin absorbs the oil very quickly. You can also spread poison ivy on your own body if oil is still on your fingers or under your nails and you then touch other parts of your body.

The real danger is getting a poison ivy rash from dogs that have urushiol oil on their fur, or inanimate objects, where urushiol oil can hang on for years. This can include clothing, shoes, gloves, garden tools, your dog’s leash, and more. Be careful when touching your dog after it has been rollicking in the woods. And if you suspect an object has urushiol oil on it, clean it with rubbing alcohol or soapy water.

You can’t get a rash from fluid coming out of a burst blister, although you can develop a rash after touching a dead poison ivy plant.

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How to prevent poison ivy rash from spreading

If you’re going outdoors and think you might come into contact with poison ivy, use an over-the-counter barrier cream as a buffer between urushiol oil and your skin. You can also protect yourself by wearing long pants, long sleeves, gloves, and boots.

If urushiol oil from a plant does gets on your skin, it could spread to other parts of your body if you touch the oil with your fingers then touch another part of your body. If you think you’ve been exposed recently, rinse your skin with lukewarm soapy water or take a cool shower (not a bath, as that could spread the oil further). Brush vigorously under your nails.

Urushiol oil can linger on inanimate objects such as clothes, shoes, rakes or other gardening tools. Wash clothes and shoes, and use rubbing alcohol or soap and water on tools.

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Can dogs get poison ivy?

Although dogs usually don’t get poison ivy rash, they can easily get urushiol oil on their fur from being in the woods or backyard, or just going for a neighborhood walk. And you may get a poison ivy rash from petting a dog. If you suspect your dog has been in contact with poison ivy, wash him or her right away while wearing rubber gloves and goggles in case they shake off the water. If you dry your dog with a towel, throw it in the washing machine and let your dog dry off fully before petting him or her again. You should also wash your dog’s leash, collar, and any other objects that may have urushiol on it.

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How to safely get rid of poison ivy plants

If there are poison ivy plants in your yard, you can get rid of them yourself or hire a professional to do it for you. If doing it yourself, make sure you can accurately identify the plant first. When you’re ready to start the eradication, wear thick gloves, boots, long sleeves, and pants to make sure you don’t get it on you. Poison ivy can be pulled out of the ground like a weed, but make sure you get the roots. Some people use an herbicide as well. Bear in mind that you can still get poison ivy rash from dead plants. Don’t burn poison ivy—smoke from the burn will contain urushiol oil. Once you’re done removing poison ivy, or at least done for the day, wash all your clothes and anything that may have come into contact with the poison ivy. And wash yourself—especially your hands—and scrub under your nails even if you’ve been wearing gloves.