Prehospital Care
Preventive measures for toxicodendron dermatitis includes using barriers. Classic preventive strategies include wearing long sleeves, long pants, and gloves. Vinyl gloves are preferred because they will not absorb the urushiol as readily as leather or fabric gloves. Rubber gloves can be permeable to urushiol.
A number of commercially available creams are marketed to prevent penetration of urushiol into the skin. The published data on these remedies are limited and conflicting. Although some protective effect is suggested, the degree of protection and the cost-to-benefit ratio are unclear.
The initial treatment of toxicodendron dermatitis is to wash the affected area as soon as possible after exposure. Washing exposed areas with copious amounts of water within 20 minutes of exposure has been shown to reduce reactivity. [11] The efficacy of washing appears to decrease over time.
Emergency Department Care
Treatment can be considered in the following three categories:
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Decontamination
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Topical/symptomatic treatment
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Immunomodulation
Decontamination
Immediate decontamination: Urushiol penetrates the skin and binds to membrane lipids within 10-20 minutes of contact. If the toxin can be removed before this occurs, reaction can be avoided.
Although multiple products are marketed for skin decontamination, they are only slightly more efficacious than soap and water. [12] Copious water is recommended because soaps can spread the urushiol oil around the skin.
It is important to instruct patients to clean their clothes and any other objects that might have been in contact with the oils.
Topical or symptomatic care
Topical preparations for symptomatic relief are the standard care for poison ivy exposure. Calamine (a combination of zinc oxide and ferric oxide), oatmeal baths, and Burow solution (an aqueous solution of aluminium triacetate, Domeboro®), all have been recommended. To prevent ground oatmeal from caking in pipes, it can be placed in a tied sock before being dropped in the bathtub.
Zanfel®, a soap mixture of ethoxylate and sodium lauroyl sarcosinate surfactants, is a product that is claimed to bind the urushiol resin for a number of days after exposure. It has been aggressively marketed. Limited data on this product show a mild benefit of up to 6 days after experimental exposure. [13]
A number of herbally based folk remedies (eg, jewelweed [14] ) have been proposed over the years and are receiving some new attention, although none can be particularly endorsed at this time. [15] A study by Abrams Motz and colleagues confirmed that jewelweed mash is effective for preventing development of dermatitis after poison ivy contact, but is less effective than soap. [16] These researchers subsequently confirmed that saponins in jewelweed are responsible for this effect. [17]
Oral antihistamines can be of some benefit for the relief of pruritus, especially in severe cases with urticarial lesions accompanying the bullae.
Low-potency topical steroids and topical antihistamines have not been shown to have any beneficial effect.
Oral analgesics (eg, acetaminophen, nonsteroidal anti-inflammatory drugs [NSAIDs]) occasionally are required for very severe cases, especially as an aid to sleep.
Immunomodulation
Systemic steroids are the standard treatment for severe toxicodendron dermatitis. These generally are given orally, although some authors prefer high-potency steroid creams (fluocinonide or clobetasol propionate applied topically twice a day for a week and then once a day for a week) if started early in the course.
Orally, various bursts of prednisone or methylprednisolone are used. These medications should be tapered off for at least 10-14 days (up to 3 wks). A study by Curtis and Lewis in 49 patients with severe poison ivy dermatitis found that patients who received a 5-day burst followed by a 10-day taper were significantly less likely to utilize other medications, compared with patients who received a burst regimen only (22.7% vs. 55.6%, P = 0.02). The longer regimen consisted of 5 days of 40 mg oral prednisone daily followed by the following taper [18] :
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30 mg daily for 2 days
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20 mg daily for 2 days
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10 mg daily for 2 days
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5 mg daily for 4 days
Early withdrawal of steroid therapy can lead to a recrudescence of the lesions. Therefore, avoid premade dose packs, and emphasize to the patient the importance of finishing his or her course of medication.
Prevention
Avoid exposure. Protective clothing, such as gloves (nonlatex), should be worn if handling the plants or contaminated objects or animals. A number of barrier creams and lotions are available. Although they cannot completely eliminate the reaction, they can diminish the exposure.
Long-Term Monitoring
Patients should follow up with their primary care physician. All contaminated clothing and articles should be washed. Pets that have been exposed should be bathed well to remove the oil from their fur. Precautions include watching for secondary bacterial infection of skin lesions.
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Forearm approximately 10 days after exposure to poison ivy in a garden. Note vesicles and linear areas of the rash.
