A poison ivy rash is a type of skin
irritation called allergic contact dermatitis. Poison ivy rash is caused
by a sensitivity to an irritant found in poison ivy and similar toxic
plants, such as poison oak and poison sumac. Each of these plants
contains an oily resin called urushiol (u-ROO-she-ol) that can irritate
the skin and cause a rash.
Although the itching from a poison ivy rash can be quite bothersome, the
good news is that a poison ivy rash or one caused by poison oak or
poison sumac generally isn't serious. Poison ivy rash treatment consists
of self-care methods to relieve itching until the reaction disappears.
Signs and symptoms of a poison ivy rash include:
Often, the rash looks like a straight line because of the way the plant
brushes against the skin. But if you come into contact with a piece of
clothing or pet fur that has urushiol on it, the rash may be more spread
The reaction usually develops 12 to 48 hours after exposure and can last
up to eight weeks. The severity of the rash is dependent on the amount
of urushiol that gets on your skin.
In severe cases, new areas of rash may break out several days or more
after initial exposure. This may seem like the rash is spreading. But
it's more likely due to the rate at which your skin absorbed the
Your skin must come in direct contact with the plant's oil to be
affected. Blister fluid from scratching doesn't spread the rash, but
germs under your fingernails can cause a secondary bacterial infection.
When to see a doctor
See your doctor if any of the following occur:
* The reaction is severe or widespread.
* The rash affects sensitive areas of your body, such as your eyes, mouth or genitals.
* Blisters are oozing pus.
* You develop a fever greater than 100 F (37.8 C).
* The rash doesn't get better within a few weeks.
Poison ivy, poison oak and poison sumac can all cause contact dermatitis and the resulting itchy rash.
* Poison ivy is an extremely common weed-like plant that may grow as
a bush, plant or thick, tree-climbing vine. The leaves typically grow
three leaflets to a stem. Some leaves have smooth edges, while others
have a jagged, tooth-like appearance. In the fall, the leaves may turn
yellow, orange or red. Poison ivy can produce small, greenish flowers
and green or off-white berries.
* Poison oak can grow as a low plant or bush, and its leaves
resemble oak leaves. Like poison ivy, poison oak typically grows three
leaflets to a stem. Poison oak may have yellow-white berries.
* Poison sumac may be a bush or a small tree. It has two rows of leaflets on each stem and a leaflet at the tip.
The irritating substance is the same for each plant, an oily resin
called urushiol. When your skin touches the leaves of the plant, it may
absorb some of the urushiol made by the plant. Even a small amount of
urushiol can cause a reaction. Urushiol is very sticky and doesn't dry,
so it easily attaches to your skin, clothing, tools, equipment or pet's
You can get a poison ivy reaction from:
* Direct touch. If you directly touch the leaves, stem, roots or
berries of the plant, shrub or vine, you may have a reaction.
* Urushiol remaining on your skin. You may develop a poison ivy rash
after unknowingly rubbing the urushiol onto other areas of your skin.
For example, if you walk through some poison ivy then later touch your
shoes, you may get some urushiol on your hands, which you may then
transfer to your face by touching or rubbing.
* Urushiol on objects. If you touch urushiol left on an item, such
as clothing or firewood, you may have a reaction. Although animals
usually aren't affected by urushiol, if it's on your pet's fur and you
touch your pet, you may develop a poison ivy rash. Urushiol can remain
allergenic for years, especially if kept in a dry environment. So if you
put away a contaminated jacket without washing it and take it out a
year later, the oil on the jacket may still cause a reaction.
* Inhaling smoke from burning poison ivy, oak or sumac plants. Even
the smoke from burned poison ivy, poison oak and poison sumac contains
the oil and can irritate or injure your eyes or nasal passages.
A poison ivy rash itself isn't contagious. Blister fluid doesn't contain
urushiol and won't spread the rash. In addition, you can't get poison
ivy from another person unless you've had contact with urushiol that's
still on that person or on his or her clothing.
Scratching a poison ivy rash with dirty fingernails may cause a
secondary bacterial infection. This might cause pus to start oozing from
the blisters. See your doctor if this happens. Treatment for a
secondary infection generally includes antibiotics.
Read this article on Mayoclinic.com.
Expand Arrow DownPreparing for your appointment
You probably won't need medical treatment for a poison ivy rash, unless
the rash persists for more than a few weeks or you think you may have a
bacterial infection too. If you're concerned you'll probably first see
your primary care physician. However, you may be referred to a doctor
who specializes in skin disorders (dermatologist).
Because appointments can be brief, and there's often a lot of ground to
cover, it's a good idea to arrive well prepared. Here's some information
to help you get ready for your appointment, and what to expect from
What you can do
* Write down any symptoms you're experiencing, including any that
may seem unrelated to the reason for which you scheduled the
* Write down key personal information, including recent vacations or
time spent outdoors, especially if you've been hiking, gardening or
* Make a list of all medications, vitamins and supplements that you take, including information on your usual dose.
* Write down questions to ask your doctor.
Your time with your doctor is limited, so preparing a list of questions
can help you make the most of your time together. For a poison ivy rash,
some basic questions to ask your doctor include:
* What's the most likely cause of my symptoms?
* Are there other possible causes for my symptoms?
* Do I need any tests?
* How long will this rash last?
* Is it OK to scratch?
* Will scratching spread the rash?
* Will popping the blisters spread the rash?
* What treatments are available, and which do you recommend?
* What types of side effects can I expect from treatment?
* What can I do to help control the itching?
* How can I prevent this in the future?
* Are there any brochures or other printed material that I can take home with me? What Web sites do you recommend visiting?
What to expect from your doctor
Your doctor is likely to ask you a number of questions, such as:
* When did you begin experiencing symptoms?
* Have you had a similar rash in the past?
* Have you spent time outdoors recently?
* What treatment steps have you already tried?
What you can do in the meantime
A poison ivy rash will eventually go away on its own. But, the itching
can be difficult to deal with. Here are some steps you can take to help
control the itching:
* Apply an over-the-counter corticosteroid cream for the first few days.
* Apply calamine lotion.
* Take oral antihistamines, such as diphenhydramine (Benadryl, others), which may also help you sleep better.
* Soak in a cool-water bath containing a colloidal oatmeal product (Aveeno) or baking soda.
* Place cool, wet compresses on the affected area for 15 to 30 minutes several times a day.
Tests and diagnosis
You generally won't need to see your doctor for a poison ivy rash.
However, if you do visit your doctor, he or she will be able to diagnose
your rash by looking at it. No further testing is needed.
Read this article on Mayoclinic.com.
Expand Arrow DownTreatments and drugs
Poison ivy treatments are usually limited to self-care methods, and the
rash typically goes away on its own within two to four weeks. In the
meantime, you can use poison ivy remedies, such as oatmeal baths and
cool compresses, as well as over-the-counter anti-itch medications to
relieve your signs and symptoms.
If the rash is widespread or results in a large number of blisters, your
doctor may prescribe an oral corticosteroid, such as prednisone, for
poison ivy treatment. If a bacterial infection has developed at the rash
site, your doctor will likely give you a prescription for an oral
Read this article on Mayoclinic.com.
Expand Arrow DownLifestyle and home remedies
Once a rash has broken out, the following poison ivy remedies may help to soothe itching and swelling:
* Over-the-counter low-potency corticosteroid creams, such as hydrocortisone, applied two to four times a day
* Calamine lotion
* Oral antihistamines, such as diphenhydramine (Benadryl, others), which may also help you sleep better
* Cool-water tub soaks with over-the-counter colloidal oatmeal (Aveeno) or baking soda
* Cool, wet compresses for 15 to 30 minutes several times a day
In addition to self-care measures, such as taking an oatmeal bath, some
people may seek out alternative therapies to help control symptoms
associated with poison ivy, oak and sumac. Some treatments that have
been tried include:
* Jewelweed. This plant was used as a Native American treatment for
poison ivy. However, a randomized, controlled study found that it isn't
* Bovine cartilage cream (5 percent concentration). A study done in
the 1970s found that when applied daily, this cream helps to clear a
poison ivy rash within one to two weeks.
* Deodorant containing aluminum chlorohydrate. Spray this deodorant
on your skin and clothing before heading outdoors, and you may help
prevent urushiol from irritating your skin. Of course, it's still a good
idea to wash your skin and clothes as soon as you can if you think
you've brushed up against poison ivy.
The advice "Leaves of three, let them be" is familiar to many people,
with good reason. It's a reminder to stay away from plants that feature
three leaflets to a stem, such as poison ivy, because avoiding contact
is the best way to prevent an allergic reaction.
These suggestions may help you avoid a rash from these irritating plants:
* Identify poison ivy, poison oak and poison sumac. Learn what the
plants and leaves look like and where they're commonly found so that you
can avoid them.
* Take precautions outdoors. When hiking or engaging in other
activities that might expose you to poison ivy, try to stay on cleared
pathways. If camping, make sure you pitch your tent in an area free of
poisonous plants. Keep pets from running through wooded areas so that
urushiol doesn't accidentally stick to their fur, which you then may
touch. If you think your pet may have run through poison ivy, oak or
sumac, put on some long rubber gloves and give your pet a bath to remove
any residual urushiol.
* Remove poison ivy. In your backyard, you can use an herbicide to
get rid of poison ivy or use heavy gloves to carefully pull it out of
the ground. Note that even dead plants can cause a reaction. Afterward,
remove and wash your gloves and hands thoroughly. Don't burn poison ivy
or related plants because the urushiol can be carried by the smoke and
cause irritation or injury.
Clean anything that may be contaminated. Wearing long pants,
socks, shoes and gloves will help protect your skin, but be sure to wash
your clothing promptly with detergent — in a washing machine, if
possible — if you think you've come into contact with poison ivy. Handle
contaminated clothes carefully so that you don't transfer the urushiol
to furniture, rugs or appliances.
In addition, wash any other contaminated items, such as outdoor
gear, garden tools, jewelry, shoes and even shoelaces, as soon as
possible. If you must wait to wash any contaminated items, seal them up
in a plastic bag or container to avoid contamination of other items. Dry
cleaning also will get rid of urushiol, but be sure to let your dry
cleaner know that the item may have been exposed to poison ivy.
* Wash your skin with soap and water. Gently washing off the harmful
resin from your skin, using any type of soak, within five to 10 minutes
after exposure may help avert a reaction. After an hour or so, however,
the urushiol has usually penetrated the skin and washing won't
necessarily prevent a reaction, but it may help reduce its severity. Be
sure to wash under your fingernails too.
* Apply a barrier cream. Appy an over-the-counter barrier skin cream
containing bentoquatam (Ivy Block) to protect your skin. Bentoquatam
absorbs urushiol and prevents or lessens your skin's reaction to the