Poison Ivy, Poison Oak, and Poison Sumac.

This JAMA Patient Page describes allergic skin reactions from contact with poison ivy, poison oak, and poison sumac plants, and how to treat rashes caused by these plants.

Plant Dermatitis.

Plant dermatitis is a common pathology that plagues those who work and recreate in the North American outdoors. The most common plant family to cause dermatitis is the Toxicodendron genus, which includes the plants known by the common names of poison ivy, poison oak, and poison sumac. While mortality is usually quite low for this pathology, the incidence and prevalence of the disease leads to substantial healthcare burden and financial implications across the population. The mainstays of treatment have focused on prevention, corticosteroids, and antihistamines.

Plant Dermatitis: More Than Just Poison Ivy.

Plants can cause allergic contact dermatitis (ACD), mechanical irritant contact dermatitis, chemical irritant contact dermatitis, light-mediated dermatitis, and pseudophytodermatitis. Allergic contact dermatitis to chemicals in the Toxicodendron genus, which includes poison ivy, poison oak, and poison sumac, is the most common cause of plant ACD; however, many other plants, such as Compositae, Alstroemeriaceae, and Rutaceae plants also are important causes of dermatitis. In individuals with recurrent ACD from plants other than Toxicodendron, patch testing can be used to identify the source of allergic reactions to plant species. This article provides an overview of the various plant dermatoses, common culprits of plant dermatitis, and diagnostic and therapeutic options for plant dermatoses.

Immunologic studies of poisonous Anacardiaceae: oral desensitization to poison ivy and oak urushiols in guinea pigs.

Poison ivy and oak urushiols or their components were compared with the respective esterified derivatives for efficacy in oral desensitization of Hartley guinea pigs sensitized to urushiols. The esterified derivatives produced a significantly greater degree of hyposensitization than did free urushiol counterparts. Suppression produced by esterified urushiols was of longer duration than that produced by free urushiols. Groups of sensitized guinea pigs were given high (100 mg/kg) or low (10 mg/kg) doses of a mixture of acetylated, saturated urushiol congeners over a 1-, 2-, or 3-week period. High doses produced a greater degree of hyposensitization regardless of the dosage schedule used. Low doses did not produce significant hyposensitization unless given over a shorter (1 week) schedule. Large single booster doses (33 mg/kg/week) of the acetate derivatives produced a rebound in responsiveness when given, 2 weeks following the last dose of the initial series, to animals hyposensitized with 10 mg/kg. No such rebound in sensitivity occurred in animals given a series of high initial doses.

Oral hyposensitization to poison ivy and poison oak.

We evaluated the safety and efficacy of a 1:1 mixture of pentadecylcatechol (PDC) and heptadecylcatechol (HDC) diacetate in reducing hypersensitivity to poison ivy and poison oak. The study was double-blind, parallel, randomized, and placebo controlled. The 44 subjects receiving the active drug ingested a cumulative dose of 306.5 mg over a five-week period. Subsequently, 14 patients were continued on a maintenance phase, ingesting an additional 960 mg of drug. The PDC-HDC diacetate was well tolerated, with no significant side effects. Evaluation of efficacy compared poststudy and prestudy reactions to patch tests using urushiol in doses of 0.025, 0.05, 0.125, 0.25, and 0.5 micrograms applied to the forearm. The results indicated that the induction phase as well as the maintenance phase did not induce a statistically significant hyposensitivity to urushiol, and we were thus unable to decrease sensitivity to poison ivy and poison oak in humans using orally ingested PDC-HDC diacetate.

Renal lesions accompanying poison oak dermatitis.

Renal damage associated with poison oak dermatitis is extremely rare in humans after exposure to urushiol antigen. Three renal lesions have been described: proliferative glomerulonephritis, arteritis, and membranous nephropathy. The present study reports on three patients who developed nephropathy after exposure to poison oak. One patient was studied by renal biopsy (including electron microscopy and immunofluorescence techniques) and another by autopsy findings. One of these patients had a typical membranous nephropathy, the other, proliferative glomerulonephritis with necrotizing arteritis and glomerulitis. In the patient with membranous nephropathy antibody to urushiol was discovered by passive cutaneous anaphylaxis in the guinea pig.

Dermatitis.

Dermatitis, the inflammatory response of the skin to various factors, may present in a variety of forms. Atopic dermatitis, contact dermatitis, nummular eczema, seborrhea, and stasis dermatitis, conditions with which the patient may present to the emergency department, either in the acute stage or with exacerbation of a chronic condition, are reviewed in this article.

Erythema multiforme associated with Rhus contact dermatitis.

A case of erythema multiforme and Rhus contact dermatitis is presented herein. Due to the association of nephritis and other complications with Rhus poison oak, we recommend that patients with contact dermatitis due to poison ivy who incur secondary erythema multiforme be hospitalized and closely monitored.

Poison ivy dermatitis.

Eruptions caused by poison ivy and related plants are almost always a form of allergic contact dermatitis. Usually they can be readily recognized because of their characteristic streak-or-line-like appearance. They usually clear within one to three weeks unless there is continued exposure to the allergen. Local treatment suffices in mild to moderate cases, but in more severe cases systemic corticosteroids can be added.

Treatment of toxicodendron dermatitis (poison ivy and poison oak).

Toxicodendron dermatitis results from a reaction to an oil soluble oleoresin that is present in many parts of the poison ivy and poison oak plants. Prophylactic measures include avoidance, protective clothing, barrier creams and hyposensitization. Treatments include washing the area immediately with a solvent suitable for lipids and the use of anti-inflammatory agents, especially corticosteroids.

Acupuncture for poison ivy contact dermatitis. A clinical case report.

Poison ivy contact dermatitis is fairly common in the suburbia of this country among amateur gardeners and children. It commonly inflicts its poison on the exposed parts of the limbs. The vesicular or bullous skin lesions are quite disturbingly itchy. Scratching the itchy lesions often spreads the condition by transplanting the remanent resinous toxin to other parts of the body. Though they are usually self-limiting, the intense itch is the main motivation for a patient to seek medical care. The conventional treatment is basically ineffective. During the summer of 1987 we treated four such cases of dermatitis with acupuncture upon their request to mollify their unbearable itch. They originally consulted with us for other problems. There were three males and one female. Their ages were between 29 and 63. Three cases were relatively mild and the fourth one was fairly severe. In the milder cases, their itch subsided in a few hours and skin lesions were healed in about two days after one treatment. In the severe case the itch subsided in about two days and most of the skin lesions dried up in four days after the first treatment and were healed almost completely after three sessions of acupuncture treatment. The plausible anti-inflammatory mechanism of acupuncture with the involvement of ACTH and/or cortisol was discussed.

Identification and treatment of poison ivy dermatitis.

Poison ivy dermatitis is an acute self-limiting problem of two or three weeks' duration that can cause significant discomfort. Poison ivy, poison oak and poison sumac cause more cases of allergic contact dermatitis than all the other contact allergens combined. Treatment of poison ivy dermatitis depends on the severity of the reaction. The nurse practitioner can manage the majority of poison ivy cases. However, if there is systemic involvement, a physician consultation is necessary. The patient can best be assisted by assessing the severity of the dermatitis, prescribing an appropriate supportive therapy and teaching preventive measures.

Heracleum mantegazzianum and Toxicodendron succedaneum: plants of human health significance in New Zealand and the National Pest Plant Accord.

New Zealand's National Pest Plant Accord (NPPA) is a voluntary and cooperative agreement between industry, regional councils, and central government departments with biosecurity responsibilities (primarily the Ministry of Agriculture and Forestry and the Department of Conservation). Plant species included in the NPPA are declared unwanted organisms under the Biosecurity Act 1993, which prevents their sale, propagation, or distribution across the country. Although MAF Biosecurity New Zealand (the lead agency in New Zealand's biosecurity system) has evaluated the potential human health impacts of 202 species considered for inclusion in the NPPA, two species were examined primarily due to their significance to human health: Heracleum mantegazzianum (giant hogweed, cow parsnip, wild parsnip) and Toxicodendron succedaneum (rhus tree, wax tree, Japanese wax tree). As a result of this process, H. mantegazzianum has been listed in the NPPA. In contrast, T. succedaneum was not included in the NPPA, as the latter was deemed to be an inappropriate mechanism for its control. In this article the NPPA process is outlined, and the adverse impacts on human health of these two species are discussed--including symptoms, treatment, and possible management measures.

Toxicodendron dermatitis in the UK.

BACKGROUND: We present two cases of Toxicodendron dermatitis, one acquired in the United States but presenting in the United Kingdom (UK), the other a recurrent dermatitis following importation of the plant to the UK. Poison ivy, poison oak and poison sumac are native to North America and belong to the genus Toxicodendron. This group of plants is of interest to the dermatologist because they contain a mixture of potent sensitisers which cause a severe allergic contact dermatitis. CONCLUSIONS: The dermatitis can present to the dermatologist in Europe after an individual has been in contact with the plant whilst visiting an endemic area. The plants have the potential to grow in Europe and it is therefore possible for an individual to be sensitised and subsequently to develop the rash without leaving the continent.