Poison Ivy, Oak and Sumac

What is poison ivy, oak, and sumac?

Poison Ivy

Poison ivy, poison oak and poison sumac are plants that can cause a skin rash called allergic contact dermatitis. When they touch your skin.  The red, uncomfortable, and itchy rash often shows up in lines or streaks and is marked by fluid-filled bumps (blisters) or large raised areas (hives).  It is the most common skin problem caused by contact with plants (plant dermatitis).

What causes a poison ivy, oak, or sumac rash?

The rash is caused by contact with an oil (urushiol) found in poison ivy, oak, or sumac. The oil is present in all parts of the plants, including the leaves, stems, flowers, berries, and roots. Urushiol is an allergen, so the rash is actually an allergic reaction to the oil in these plants. Indirect contact with urushiol can also cause the rash. This may happen when you touch clothing, pet fur, sporting gear, gardening tools, or other objects that have come in contact with one of these plants. But urushiol does not cause a rash on everyone who gets it on his or her skin.

What are the symptoms of the rash?

The usual symptoms of the rash are:

• 

  Poison Sumac

  Itchy skin where the plant touched your skin.

• Red streaks or general redness where the plant brushed against the skin.
• Small bumps or larger raised areas (hives)
• Blisters filled with fluid that may leak out.

The rash usually appears 8 to 48 hours after your contact with the urushiol. But it can occur from 5 hours to 15 days after touching the plant. The rash usually takes more than a week to show up the first time you get urushiol on your skin. But the rash develops much more quickly (within 1 to 2 days) after later contacts. The rash will continue to develop in new areas over several days but only on the parts of your skin that had contact with the urushiol or those parts where the urushiol was spread by touching.

The rash is not contagious. You cannot catch or spread a rash after it appears, even if you touch it or the blister fluid, because the urushiol will already be absorbed or washed off the skin. The rash may seem to be spreading, but either it is still developing from earlier contact or you have touched something that still has urushiol on it.

The more urushiol you come in contact with, the more severe your skin reaction. Severe reactions to smaller amounts of urushiol also may occur in people who are highly sensitive to urushiol. Serious symptoms may include:

• Swelling of the face, mouth, neck, genitals, or eyelids (which may prevent the eyes from opening).
• Widespread, large blisters that ooze large amounts of fluid.

Without treatment, the rash usually lasts about 10 days to 3 weeks. But in people who are very sensitive to urushiol, the rash may take up to 6 weeks to heal.

How is the rash diagnosed?

The rash usually is diagnosed during a physical exam. Your doctor will examine the rash and ask questions to find out when you were exposed to the plant and how long it took the rash to develop. If you are not sure whether you were exposed to a plant, he or she will ask about your outdoor activities, work, and hobbies.

How is the rash treated?

Most poison ivy, oak, or sumac rashes can be treated successfully at home. Initial treatment consists of washing the area with water immediately after contact with the plants. To relieve symptoms, use wet compresses and take cool baths

How can I prevent the rash from poison ivy, oak, and sumac?

The best way to prevent the rash is to learn to identify and avoid the plants. When you cannot avoid contact with the plants, heavy clothing (long pants, long-sleeved shirt, and vinyl gloves) and barrier creams or lotions may help protect you.

Habitat and description of Poison Ivy, Oak and Sumac:

Poison Ivy, Oak and Sumac are found throughout the continental United States. In general, poison ivy grows east of the Rocky Mountains, poison oak west of the Rocky Mountains, and poison sumac in the southeastern United States.

The plants may look different depending on the season and the area where they are growing. But all of these plants have small white, tan, cream, or yellow berries in the fall. Their berries can help distinguish them from harmless but similar plants.

After the leaves have fallen off, these plants can sometimes be identified by the black color on areas where the oil in the plant (urushiol) has been exposed to air.

Poison ivy

Poison ivy is found everywhere in the United States except Alaska and Hawaii. It is most common in the eastern and midwestern states. It is less common outside the United States, but still found on every continent.

• Usually has three broad, spoon-shaped leaves or leaflets, but it can have more. The phrase, “Leaves of three? Let it be.” may help you remember what poison ivy looks like.
• Grows as a climbing vine or a low, spreading vine that sprawls through grass (more common in eastern states) or as a shrub (more common in northern states, Canada, and the Great Lakes region).
• Often grows along rivers, lakefronts, and ocean beaches.
• Has bright red leaves and white or cream berries in the autumn.

Poison oak

Poison oak is most common in the western United States, although it is also found in eastern states. It rarely is found in midwestern states.

• Has leaves that look like oak leaves, usually three leaflets but sometimes up to seven per leaf group.
• Grows as a vine or a shrub.

Poison sumac

Poison sumac is much less common than poison ivy or poison oak. It is found in wooded, swampy areas, such as Florida and parts of other southeastern states. It is also found in wet, wooded areas in the northern United States.

• Has 7 to 13 leaflets per leaf stem. The leaves have smooth edges and pointed tips.
• Grows as a shrub or small tree.

Where they are not found

• None of these plants grow well above 4000ft, so the higher elevations in places such as the Rocky Mountains are relatively free of them.
• None of these plants grow well in deserts, except along the banks of rivers, streams, and ponds. But heavy rainfall can make a dormant plant grow again, even in a desert.
• Hawaii does not have any of these plants, although other plants that cause a skin rash are found on the islands. For example, mango trees grow in Hawaii, and the skin of mangoes contains the same allergenic oil (urushiol) as these plants.
• These plants do not grow in Alaska, and they are rarely found in the rainforests of Washington state and Oregon.

Poison Ivy, Oak, or Sumac – Exams and Tests

A rash from these plants usually is diagnosed through a physical exam and questions about your outdoor activities. Your doctor will examine the rash to decide which kind of plant caused it and ask about:

• The length of time between possible exposure and development of the rash.
• The length of time you were out in the sun.
• What you were doing when the exposure may have occurred (hiking, for example).
• Other rashes you have had.
• Your job and your hobbies.

Diagnosis is harder when there are no clues that you have been in contact with the plant. Sometimes indirect contact with the plant oil (urushiol) causes the rash. Urushiol that is on clothing or other objects may spread to your skin months after initial contact. If a bacterial infection is suspected, your doctor may take a sample of blister fluid for a culture.

If your primary care doctor is not sure of the cause, you may need to see a dermatologist for a direct patch skin test. In this test, small amounts of allergens are placed on the skin and covered with a bandage for several days. The patch is then removed and the skin is examined for reactions.

Poison Ivy, Oak, or Sumac – Treatment Overview

The rash from Poison Ivy, Oak or Sumac generally is mild and can be treated at home. Home treatment for the rash usually helps relieve symptoms but does not speed up healing of the rash.

• If you know you had contact with one of these plants immediately wash the skin that may have touched the plant. Sometimes the rash can be completely avoided by washing the affected areas with plenty of water within 10 or 15 minutes of contact. You could also try using a product (such as Tecnu or Zanfel) that is designed to remove the oil from your skin.
• To relieve itching apply wet compresses or soak the area in cool water. Antihistamine pills or calamine lotion may help relieve symptoms.
• If you have a moderate to severe rash, you may need to see your doctor. A frequent complication of the rash is infection.  If this occurs, your doctor will probably prescribe an antibiotic cream that you spread on the affected skin if the infection is small. Otherwise, you may need antibiotic pills or a shot. To Prevent and infection try to avoid itching to minimize the possibility of opening the skin and spreading bacteria.

Regardless of what type of treatment is used after a rash develops, the length of time it lasts will vary from person to person.

Poison Ivy, Oak, or Sumac – Home Treatment

The rash is generally is mild and can be treated at home. Home treatment for the rash usually helps relieve symptoms rather than speeding up the time it takes the rash to heal.

• If you know you had contact with one of the plants immediately wash the skin that may have touched the plant. Sometimes the rash can be completely avoided by washing the affected areas with plenty of water within 10 or 15 minutes of contact. Most of the oil is absorbed into the skin in the first 30 minutes. Clothing should also be thoroughly washed right away. Contaminated surfaces should be cleaned with rubbing alcohol.
• To relieve itching apply wet compresses or soak the area in cool water. Calamine lotion may help relieve symptoms.
• To prevent infection try not to scratch the rash. Also, cut your fingernails short to minimize the possibility of opening the skin and spreading bacteria.

Poison Ivy, Oak, or Sumac – When To Call a Doctor

Call a doctor if:

• The rash causes great discomfort that is not relieved by home treatment (for instance, you apply Calamine lotion to the rash, but itching continues to make it difficult to sleep)
• The rash shows signs of infection such as pain, swelling, or warmth around the affected area.
• The rash covers a very large area of the body.
• Home treatment causes the rash to get worse or to come back after nearly disappearing.
• Rashes occur frequently, and you are not sure what is causing them. (The rashes may be caused by another kind of plant.)
• Your mouth is swollen or you think the rash has spread to your mouth.
• The rash has spread to your face, particularly around an eye.
• You have a rash and a weakened immune system

Call 911 if you are having hard time breathing.

Watchful Waiting

Watchful waiting is a wait-and-see approach. If the rash is not severe, watchful waiting may be appropriate. Home treatment may be used to relieve symptoms. Dark spots may develop, but this is not serious.

Watchful waiting is not appropriate if the rash develops over your entire body, becomes infected, or reappears or gets worse after using medicine. See your doctor.

Who To See

You may not need to see a doctor for the rash. But if you want to find the cause of the rash or if you want to treat an uncomfortable, severe, or infected rash, you may choose to see:

• A Family Medicine Doctor
• A Pediatrician
• A Dermatologist.