What do the plants look like?
There are three types of plants that can cause a skin rash to develop when your child comes in contact with them. Sometimes we tend to lump them all together and refer to them as "poison ivy". The three culprits are known separately as poison ivy, poison oak, and poison sumac. Each of these contains toxicodendrol within their stems and leaves. Toxicodendrol is an oil that contains an active ingredient known as urushiol. The urushiol is the chemical that actually causes the skin to have a reaction known as contact dermatitis. A contact dermatitis can be any inflammation of the skin that is caused by physical contact with something else, usually a chemical of some sort.
Toxicodendrol is located within the plant's roots, stems, leaves, and berries. It is not found on the outside of the plant! The plant actually needs to be broken, or injured in some way, so the oil (sap) can leak out onto the outside of plant. If your child walked by or brushed a plant that was completely intact, he would not be exposed to the oil. The problem is that it is very difficult to tell whether or not a plant is damaged. By the time you have figured it out, you might have exposed yourself!
Poison Ivy comes in groups of three leaves. They are lobed-shaped and are found in almost all parts of the U.S. Poison oak looks like an oak leaf and is found along the Pacific coast and parts of the East Coast of the United States. Poison oak is generally found growing in sandy soil. Poison sumac is also found in the eastern and southern U.S. and grows as either a shrub or small tree, usually in damp areas near swamps or ponds.
Reactions, treatment, and prevention are the same for all three plants, but poison ivy will be the focus.
How do the kids actually get the rash?
Your child does not actually have to come in contact with an injured plant to become exposed to urushiol. Anything the oil gets onto can potentially cause a reaction. Oil can remain active for months on gardening tools, sports equipment, shoes, and clothing. It can also be transmitted by touching a contaminated pet. Wherever this oil comes in contact with your child's skin is a possible future site for the rash to develop.
Do not ever burn poison ivy or a related plant to try to rid your yard of it. When burned, the urushiol can become airborne and, if inhaled, can cause serious reactions both outside the body and inside the body in the nose, mouth, and lungs!
Does it spread? What if the blisters pop?
The rash caused by poison ivy, poison oak, and poison sumac does not spread. The only places the rash will develop are in the locations where the oil has come in contact with the skin. Sometimes one area may erupt first and other areas a day later, giving the impression of spreading. However, this is not the case. Your child could also re-expose himself to oil by touching a toy, the hose, gardening tool or the dog that still had some plant oil on it.
Some people believe that poison ivy can be spread by breaking open the blisters that form on the skin. This is also not true. Blisters contain fluid, mostly water, from your body, that forms at the reaction site. Your child's own body is trying to protect itself by forming a layer of fluid between the damaged skin and the healthy skin under it. Although popping these blisters will not spread the poison ivy, it can cause secondary infections if done so too early in the course of the rash. This means that bacteria can "set up shop" and cause an infection if the blisters are popped, exposing the underlying area. If your child accidentally pops a blister or if the blisters are extremely large and uncomfortable, contact your child's physician.
Once they have it!
A skin reaction to poison ivy occurs in two phases. When your child is first exposed to the plant's oils, a sensitization phase occurs. During this phase, the plant's toxic allergen, urushiol, is introduced to the body's immune system. At this initial exposure, no rash will appear. At the second exposure, the elicitation phase, usually 2-3 days (but not less than 12 hours) from the time your child touches the oil, a visible rash (poison ivy rash) will occur.
The rash may appear in lines or streaks or as a cluster of lesions, depending on how the oil was introduced to the skin. The rash may erupt in one area of the body first and in other areas much later. The normal progression of the rash starts as redness and swelling and develops into raised blistered areas from the collection of fluids under the skin. Eventually, the area oozes, dries up and crusts over. The first phase is the itchiest and often gives a burning sensation. Most cases of poison ivy will run 2-3 weeks from beginning to end.
Preventing Poison Ivy
Obviously, the best way to prevent a poison ivy outbreak is to avoid the plant and its oils. Wear long pants and sneakers or shoes instead of shorts and sandals when walking in a wooded area, or an area where the plants are likely to be growing, with your children. Be careful to check where you are sitting and walking. After coming indoors, wash your child's clothing in water and detergent to remove any oils that may have been deposited. Then wash your hands and your children's hands with soap and water. If you suspect any other area of the body was exposed, wash thoroughly with soap and water immediately. It is important to wash the area as soon as possible. Once the oil comes into contact with the skin, it is absorbed rapidly and must be washed off within 5-10 minutes of exposure in order to prevent the rash from developing.
Any objects (i.e. hoses, garden tools, coolers, etc) that may be contaminated with plant oils should be cleaned with rubbing alcohol. If you know you have poison ivy plants in your yard, they can be removed physically or with a herbicide chemical available at most garden stores. Spraying should be done before the middle of August, after which, the plants become dormant and the sprays are no longer effective. Follow the directions on the specific product you purchase or consult with your garden specialist for more information. Do not burn these plants. Oils can become airborne and, if inhaled, can cause serious complications in the nose, mouth and lungs.
There has been some success in preventing poison ivy rashes with "barrier" creams. These products are applied to the skin before your child goes outside and they protect the skin from exposure to the plant's oils. One product called IvyBlock®, contains an ingredient called bentoquatum, and needs to be applied before going outside and reapplied every few hours afterward during the period of time your child is exposed. Read the product label for specific instructions. This product works fairly well, but is not 100% effective, so other precautions will still need to be taken to minimize exposure.
Treatment Objectives
It is important to act quickly if you suspect that your child has been exposed. The first idea behind treating poison ivy is to protect the skin during the initial phase of the rash. Secondly, keep the affected area clean to prevent a secondary (bacterial) infection from developing. Thirdly, try to relieve some of the itching and discomfort for your child to prevent excessive scratching which can lead to possible bacterial infection.
To protect the skin during the initial stage, zinc oxide or calamine lotion may be used. Be careful not to use a product that also contains diphenhydramine (an antihistamine) on skin with open sores or blisters. Too much diphenhydramine may be absorbed through the skin and is not tolerated well by children. Use caution with products containing anesthetics, such as benzocaine, as well. Some children can develop a sensitivity to both of these drugs when used on open, blistered skin, and they can actually worsen the rash and cause a burning sensation.
Giving your child a bath in warm or cool water may offer some relief. Soaks or wet dressings of saline solutions, sodium bicarbonate (baking soda), or Burow's solution can be applied a few times a day. Ask your pharmacist or pediatrician for instructions on how to prepare the solutions to be used with these dressings to ensure the correct concentrations.
To keep the affected area clean, it is a good idea to clip your child's fingernails short. This will prevent any dirt and bacteria under the nails from getting into the sores being scratched.
Treatment Options:
Astringents
Astringents help to dry out and soothe a poison ivy rash. They help minimize oozing, reduce inflammation, and promote healing. Zinc oxide and calamine lotions are mild astringents that protect skin during the initial phase. Burow's solution (aluminum acetate) diluted with water can also be used as a wet dressing a few times a day. An example of a wet dressing is a sterile cotton pad soaked in the Burow's solution and then placed on the rash. For specific instructions on its use and information on how to properly dilute the Burow's powder packet or tablets, ask your pharmacist or pediatrician. Burow's solution should not be used longer than 5-7 days. Other products that can help dry up the oozing blisters include baking soda and oatmeal baths.
Hydrocortisone
Hydrocortisone cream is effective in relieving itching associated with poison ivy and related rashes. A 0.5% or 1% cream is available over-the-counter (without a prescription). The ointment form should be avoided, as it is too greasy and does not allow the rash to ooze and dry out. Hydrocortisone works by suppressing many of the reactions within the skin cells that cause inflammation and symptoms that go along with it such as swelling, redness, and itching.
Apply hydrocortisone cream in a thin film and do not use over large areas of the body, especially in children.. While hydrocortisone is considered to be a low-potency topical steroid, it is still a potent drug and should be used carefully. One concern when giving your child hydrocortisone, even in a topical form, is that some may be absorbed into the body and cause side effects. The amount absorbed depends on several factors including the condition of the skin, and the area of skin that is covered with hydrocortisone. The risk of serious side effects occurring with hydrocortisone is very minimal, if used according to the instructions given to you by your pediatrician or pharmacist.
Antihistamines
Occasionally, diphenhydramine and other antihistamines are used to treat the itchiness associated with the poison ivy rash. It is not a good idea to use topical creams or lotions containing antihistamines on children who have open sores or blistered skin. Too much of the antihistamine can be absorbed through the skin and it has the potential to cause toxic psychosis. Children are especially susceptible to this phenomenon. There is also some question as to how big a role histamine actually plays in a contact dermatitis reaction such as poison ivy. It is thought that perhaps the role of histamine is not that great. If this is true, then by blocking the histamine (with an antihistamine), these products may only offer limited benefits anyway.
Sometimes antihistamines used topically can aggravate a poison ivy rash and make it more uncomfortable and may also sensitize your child to the drug. If this occurs, wash the affected area thoroughly with water and contact your child's physician.
Use of antihistamines taken by mouth may be more beneficial for your child than the topical versions, however, oral antihistamines should not be given to a child who has become sensitized to the topical form. Consult with your child's pediatrician or other physician about this option if your child is suffering from excessive itching.
Local Anesthetics
Local anesthetics are compounds that provide a "numbing" sensation to the skin and can provide relief from itching or painful, sunburned skin. Examples of local anesthetics are benzocaine, pramoxine, and tetracaine. These compounds are used externally (outside the body) and are commonly found in certain topical products for treating poison ivy.
The problem with applying local anesthetics to poison ivy is that they can actually cause the rash to worsen by causing a sensitivity to develop. If this happens, the affected area should be washed thoroughly. Discontinue use of the product.
When to see your pediatrician
Children who have a severe case of poison ivy should see their pediatrician or other physician. Severe cases include those spread over a large portion of the body, any time there is poison ivy near or around the eyes, or when there is excessive swelling associated with the rash. See your child's doctor if you notice your child's rash is not showing signs of improving within 7 days, appears to be worsening, or your child develops a fever. This could be signs of a secondary infection developing in addition to the poison ivy and may need to be treated with an antibiotic.
Some children with a severe rash (excessive swelling and/or involvement over a large portion of the body), may need to be treated with prescription medicines known as anti-inflammatory steroids taken by mouth. Use of these steroids is only for a short period of time (usually a week or two) and the regimen is given in doses that taper down over that period of time to minimize side effects.
References:
Drug Facts and Comparisons, JB Lippincott Company, 53rd edition, 1999.
Knodel LC. Nonprescription Products: Formulations & Features "98-99. American Pharmaceutical Association, 1998.
Nonprescription Products: Patient Assessment Book, Handbook of Nonprescription Drugs. American Pharmaceutical Association, 11th edition (1997);383-88.
Taketomo CK, Hodding JH, Kraus DM. Pediatric Dosage Handbook, Lexi-Comp, 5th edition, 1998.
Wuest JR, Mueller R, Bennett A, Eastman S, Fant W. 1996 Pharmacist's Reference For Patient Counseling. Drug Store News, 1995, Vol.5(12):98.
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Seasonal page written by pharmacists at KidsMeds, (June 1999) Revised June 2008
Disclaimer: The above information is intended for educational purposes only and is not intended to replace the medical advice given to you by your child's own pediatrician, pharmacist, or other health professional.
copyright 1999. KidsMeds
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