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Poison Ivy, Poison Oak, Poison Sumac: The Rashes

Poison Ivy, Poison Oak, Poison Sumac: The Rashes

What is poison ivy?

Poison ivy (Toxicodendron radicans) is a popular plant known for causing rashes and skin irritation when one comes in contact with it.

Poison ivy is a woody shrub or vine that is found in either shady or sunny locations. It can grow up to six feet tall as a shrub, or 150 feet tall as a vine. The reason why poison ivy is poisonous is that it contains urushiol oil. When a person touches a poison ivy plant and urushiol oil makes contact with his or her skin, irritation will take place. Urushiol oil is always present on the plant, all year round, even during winter when it produces no leaves or fruit.

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While poison ivy can come in different forms, there is one distinct feature found in all poison ivy plants: their three leaflets. There will always be three leaflets that are two to six inches long, either toothed or smooth.

The leaves have a reddish tinge that glows during springtime and then turn green as the leaves grow older. When they are about to drop (usually in the fall), they turn either red or purple.

Poison ivy also bears flowers and fruit, which is an important food source to deer and birds. The fruits are berrylike with a white, polished coating. But they are also considered poisonous to humans, causing a swollen throat that may close up.


What is poison oak?

Poison oak (Toxicodendron pubescent) is also known as the Atlantic poison oak, the oak leaf, or oak leaf poison ivy. The oak is a low-growing shrub that stands around three feet tall. It's usually found in dry and sunny locations, not being able to grow under heavy shade.

Similar to poison ivy, a poison oak shrub has three leaflets, with the stems of the main leaflet being longer than the other two that connect all three together.

What makes poison oak distinguishable from poison ivy is its lobed leaves. The middle (usually terminal) leaflet is evenly lobed, while the other two leaflets are irregularly lobed. There is no exact leaf size, but the average length is around six inches long.

Another feature found on the poison oak is the fine hair coating found in the stems and leaflets.

The leaflets have a reddish tinge during spring and they turn green as they age, just like poison ivy. But once the leaves are about to drop (during fall), they turn yellow or red.

Poison oak also bears small, white flowers, and ripe fruit that's round, light tan, and polished. These flowers and fruits come in clusters.

What is poison sumac?

Poison sumac (Toxicodendron vernix) is more poisonous than either poison ivy or poison oak, causing more intense skin irritation when one comes in contact with it. It's a deciduous shrub or tree that can grow up to twenty feet tall. It has a scanty and open form, found in swamps and wet areas. These plants are usually found in shady forests or pine woods.

What makes poison sumac different from the other two poisonous plants isn't just its form, but its leaflets. It consists of 7 to 13 leaflets, arranged in pairs, and there is one lone leaflet at the end of the stem.

The stems and petioles are reddish, while the leaflets have an elongated and oval shape. The leaflets are usually two to four inches long with a smooth texture.

The leaves turn bright orange come springtime and turn dark green on the upper surface and pale green underneath as they age. Come the fall season, the leaves turn into a red-orange or russet shade.

Poison sumac also bears flowers, which grow in clusters. They turn from ivory-white flowers to gray fruits, round and polished. These fruits hang in loose clusters, 10-12 inches long. Just like poison oak and poison ivy, these flowers and fruits are poisonous to humans.

What are the differences between the rashes?

There is no distinguishable difference between the rashes, as they are caused by the same poisonous oil - urushiol oil. What would make the rashes differ is how allergic people are to the oil, or how intense the contact with the plant was. However, the type of the plant - whether it be poison ivy, poison oak, or poison sumac - will not make the difference in the rash or skin's reaction.

The reason poison sumac is considered the most poisonous is its commonness around the world, as well as how easy it is to make contact with it due to its many leaves per stem.

The rashes can only be caused by the plant oil itself, if you are allergic to the oil. An allergy to urushiol oil is very common, and some people are more allergic to it than others.

Studies show that animals do not have an allergic reaction when they come in contact with the plant. This may be due to the protection the animal's fur affords, while those animals like birds and deer who eat the leaves, flowers, and fruits of these plants are just immune to the oil.

What are the similarities between the rashes?

There is no distinguishable difference among the three plants' rashes. All of the rashes are similar, as are the symptoms you may experience if you did come in contact with any of these three plants.

What you will see are red rashes that may turn into bumps and blisters after a few days. As mentioned, the skin irritation will begin after a few hours to days after contact. It depends on how much oil you came in contact with, as well as the thickness and sensitivity of your skin. It will appear on the areas of skin that touched the plant and its oil.

What do the rashes look like?

While you will experience a host of physical symptoms after making contact with either poison ivy, oak, or sumac, the rashes will be similar and look like this:

  • The rashes will always be red and itchy: While they can spread around your body, they are mostly on the parts affected or touched by the oil. At first, they will appear like normal rashes or some small bumps.
  • Itchiness around the skin: Once the rashes begin to appear, they will start becoming itchier and more painful.
  • Red streaks will appear around the skin areas brushed by the poisonous oil.
  • Bumps and blisters will begin to form. The blisters may ooze out clear liquid or pus, with the latter being a serious issue.
  • Swelling and hives may also occur. This is similar to the rashes and blisters that will also likely form.

The rash can come after a few hours or days upon contact, but will quickly settle down after another few days, with the itchiness lessening. It will start healing after a week, and will take about a few weeks to fully clear up.

To prevent the rashes from happening, what you can do is always wear protective clothing or lotions that will guard you from the plants and their oils.

What are the symptoms of a poison ivy rash?

If you have come in contact with poison ivy, you may experience the following symptoms:

  • Redness - Red streaks show up where the plant has met the skin.
  • Small bumps or raised areas
  • Itching
  • Swelling
  • Blisters - These may or may not leak fluid.
  • Difficulty breathing

Some people suffer from more serious symptoms because of severe allergies to the urushiol oil. These symptoms include:

  • Trouble breathing
  • Severe swelling around the face or genitals. Eyelids swell shut if the allergy is that intense.
  • Many blisters that ooze liquid

If one begins to suffer from any of these serious symptoms, then they will need to get medical attention right away.

You may also have rashes on your skin that develop about a week after you come in contact with the oil. The rash can last up to three weeks. It might even last up to six weeks, if the case is serious.

The severity of the rash depends on how you came in contact with the plant. The rash may be worse if contact with the plant lasted for a long time, and if many parts of your body were in contact with the plant, your rash may appear larger, all over your body.

What are the symptoms of a poison oak rash?

If you are allergic to urushiol oil and have come in contact with poison oak, you may experience any of the following symptoms:

  • Skin rash: This is also known as dermatitis. The rashes turn red and will get itchier as time goes by. It is worse in the body parts that came in contact with the plant.
  • Bumps: They may turn into large blisters that ooze out liquid, then dry up and form a crust a few days after.
  • Stinging
  • Itchiness
  • Minor skin irritation

There are people who may experience a life-threatening allergic reaction due to a strong allergy to poison oak. Here are the more serious symptoms:

  • Difficulty in breathing
  • Hard time swallowing
  • Swelling of the face and eyes
  • Rashes around the genitals or face, usually around the lips and eyes
  • Rash that covers over 1/4 of the body
  • Infections that include pus, or yellow fluid, or a liquid with odor, leaking from blisters
  • Fever
  • Headache
  • Nausea
  • Swollen lymph nodes

These are life-threatening symptoms and will need immediate medical attention if experienced.

These symptoms come after one to six days of having come in contact with the poison oak. Usually, people experience the symptoms within a day or two. If you have a rash, then it will peak in about a week after contact with the poison ivy. The rash usually lasts for about five to twelve days. Sometimes, it can last for over a month if you are highly sensitive to urushiol oil.

What are the symptoms of a poison sumac rash?

Similar to poison ivy and oak, poison sumac rashes have the following symptoms:

  • Red and itchy bumps or blisters
  • Red rashes in striped formation
  • Skin inflammation, burning sensation, and/or swelling

There are more severe symptoms if the person is highly allergic to poison sumac:

  • Difficulty breathing due to blocked airways
  • Swollen eyelids to the point of not being able to see

If someone is suffering from a major allergic reaction to poison sumac, immediate medical attention is needed.

The severity of the symptoms will depend on how allergic the person is, as well as how he or she made contact with the poison sumac. In rare cases, the symptoms may last for over a month. Usually, they will last for a few days to three weeks.

These symptoms are not contagious and can't transfer from one person to another upon human to human contact. You will only develop a rash if you come in contact with the oil itself.

How can I tell the difference?

The rashes of poison ivy, oak, and sumac are indistinguishable. This is because the rashes are all due to the same poisonous factor, urushiol oil, which is the culprit of the allergic reactions. While the plants are different, all three come from the same family containing urushiol oil, and will cause similar symptoms and rashes. But what you can do to know the difference is to evaluate where you think you got the rash. Before distinguishing the rash or symptoms you feel, it's best to backtrack and identify the culprit. You can easily tell the plants apart by checking out their color or leaves.

If you aren't sure about the differences between the rashes or which plant you came in contact with, you don't need to worry. Their remedies and medicines are similar. However, it can be helpful to find out which plant you got the rash from in order to avoid going near the area where you came in contact with the plant.

You will be able to treat any of these rashes at home with cool baths, wet compresses, and calamine lotion. You can also purchase over-the-counter medicine that will help treat the rash and alleviate the symptoms or pain. In case the rash starts to spread to other areas, or you feel worse after a few days, then it's time to seek help from a medical professional as you are likely experiencing a more serious allergy to the urushiol oil.