Poison Oak, Poison Ivy, Poison Sumac: Stop the Itch

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Poison Ivy, Oak,or Sumac - Topic Overview



What are poison ivy, oak, and sumac?


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:

  • 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.1 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. Nonprescription antihistamines and calamine lotion also may help relieve symptoms. 

Fire in the Hole Multi-Itch Spray has proven effective in helping to lessen the intense itch associated with the swelling and blisters caused by exposure. The amino acid complex in Fire in the Hole helps to quiet down redness, help moisturize skin and help soothe the irritation that makes this type of reaction so painful.

Moderate or severe cases of the rash may require treatment by a doctor, who may prescribe corticosteroid pills, creams, ointments, or shots (injections).


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.


Poison Ivy, Oak or Sumac - Treatment Overview


The rash (allergic contact dermatitis) 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 areas of 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 and help dry blisters, 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. He or she may prescribe corticosteroid pills. These medicines may help improve or clear up the rash more quickly. Prescription corticosteroid creams, ointments, gels, or shots may also be used.


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 infection, try not to scratch the rash. Cut your fingernails short 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 - Prevention


Only the oil (urushiol) from poison ivy, oak, or sumac plants can cause a rash (allergic contact dermatitis). The best way to avoid contact with urushiol and getting a rash is to avoid the plants.

  • Learn to recognize these plants, especially those near where you live. The plants may look different depending on the season and the area where they are growing. A county agricultural extension service may be able to help you identify the plants in your area. See a picture of poison ivy, oak, and sumac leaves.
  • Even though their appearance changes with the seasons, the plants usually contain the same amount of urushiol year-round, even in the winter when they only appear as bare sticks. Black areas on the plants may help you identify them in the winter (urushiol turns black when exposed to air). Living, dormant, and dead plants all contain urushiol, although dead leaves do not contain a lot of it.
  • You may also try to remove the plants when appropriate. Never handle these plants without vinyl gloves (urushiol can penetrate rubber).
  • When you cannot avoid being near poison ivy, heavy clothing (long pants, long sleeves, enclosed footwear) may help prevent the oil from touching your skin. Clothing or any other object that has touched the plant must be handled carefully and washed thoroughly.
  • If you are often in areas where poison ivy, oak, or sumac grows, you may want to get a product (such as Tecnu or Zanfel) that is designed to remove the plant oil (urushiol) from your skin.
  • Barrier creams and lotions can be used to prevent urushiol from contacting the skin or to reduce the severity of a reaction. These creams vary in their potency and are not always effective.


If you suspect that your skin has touched poison ivy, oak, or sumac, wash the area to help prevent a reaction. Clothing and other items that may have oil on them should be thoroughly washed right away too.


Poison Ivy, Oak or Sumac - Home Treatment


The rash (allergic contact dermatitis) from poison ivy, oak, or sumac typically 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 areas of the skin that may have touched the plant. Sometimes the rash can be completely avoided by washing the affected areas with plenty of water. Clothing and other items that may have oil on them should be thoroughly washed right away too.
  • To relieve itching and help blisters dry out, apply wet compresses or soak the area in cool water. Antihistamine pills or 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 - Medications


Antihistamine pills are used to relieve the symptoms of the rash from poison ivy, oak, or sumac. Prescription medicines, such as corticosteroids, may be used for severe rashes. Medicines are also used to make the rash less severe.

Medication Choices

  • Antihistamine pills can help relieve itching and dry blisters. Examples include Benadryl (diphenhydramine), which is an over-the-counter medicine, and Vistaril(hydroxyzine), which you get by prescription.
  • Corticosteroids may be used to treat a moderate or severe rash. Corticosteroids may be given as pills, products that are spread on the skin (creams, ointments, gels), or shots.
  • Barrier creams and lotions help prevent the plant oil (urushiol) from coming in contact with the skin or reduce the severity of a reaction. These creams vary in their potency and are not always effective.
  • Fire in the Hole Multi-Itch Spray is seen by many outdoors enthusiasts and others who risk exposure to natural irritants as an absolute necessity and is often used in combination with the medication choices above to help heal the irritation and soothe the intense itching associated with it.


You may be able to use a product that dissolves urushiol, such as Tecnu or Zanfel. These products are used to wash the oil off your skin or other objects. They may reduce the severity of a reaction or prevent one.

The most common complication of poison ivy, oak, or sumac rash is a secondary infection, usually caused by scratching. When this occurs, your doctor will probably prescribe a type of topical antibiotic cream if the infection is in a small area. Otherwise, you may need systemic antibiotics, given as pills or shots.

What To Think About


The following medicines should not be used for poison ivy, oak, or sumac rash, because they can cause allergy problems of their own:

  • Antihistamines applied to the skin, such as diphenhydramine (found in Benadryl cream, spray, or gel).
  • Anesthetics applied to the skin containingbenzocaine (such as Lanacane).
  • Antibiotics containing neomycin (such as Neosporin or Poly-Pred).


Poison Ivy, Oak or Sumac - Other Treatment

Creating tolerance and reducing sensitivity



Some cultures, including certain Native American cultures, have used homeopathic treatment for poison ivy, oak, or sumac as a means of preventing the rash. Stories of successful prevention of rash through eating the leaves are common, but research studies have failed to reproduce these results without the people involved in the studies developing mild to serious side effects.

Citations

  1. Gladman AC (2006). ToxicodendrondermatitisPoison ivy, oak, and sumac. Wilderness and Environmental Medicine, 17(2): 120-128.
  2. Anderson BE, Marks JG Jr (2007). Plant-induced dermatitis. In PS Auerbach, ed., Wilderness Medicine, 5th ed., pp. 1262-1286. Philadelphia: Mosby Elsevier.
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