Leaves of Three, Let Them Be: If Only It Were That Easy

Patricia L. Jackson Allen, MS, RN, PNP, FAAN


Pediatr Nurs. 2004;30(2) 

In This Article



Prevention of contact with the Toxicodendron group of plants is the primary means of treating a child with a known sensitivity to these plants. Unfortunately, this is often difficult. The old adage "leaves of three, let them be" is only partially true. Poison ivy leaves usually come in threes but not always, are usually notched but can have smooth edges, can be 3-15 cm in length, and grow on hairy-stemmed vines or as low shrubs (see Figures 4a & b). The leaves turn bright colors in the autumn (see Figures 5a & b) and the stems have clusters of whitish-green berries. Poison ivy is most often found east of the Rocky Mountains. Poison oak is found west of the Rocky Mountains. Its leaves are 3-7 cm in length with lobulated notched edges in groups of 3, 5, or 7 leaves on small bush-like plants or vines (see Figure 6). It produces whitish flowers from late summer through fall and the leaves also turn bright colors in autumn. Poison sumac prefers boggy areas, especially in the south. The leaves are approximately 10 cm long, oval, and in clusters of 7-13 leaves angled upward on one stem of a tall shrub or small tree (see Figure 7) (Guin, Gillis, & Beaman, 1981; Tanner, 2000). All forms of Toxicodendrons produce small clusters of greenish white berries, also allergenic, along their stems in the autumn. Children cannot be expected to identify all the various forms of the Toxicodendron group but may be taught the most common forms in their immediate environment.

Figure 4a.

Poison Ivy Leaves

Figure 4b.

Poison Ivy Vine Growing on Tree

Figure 5.

Poison Ivy Leaves in Autumn

Figure 5.

Poison Ivy Leaves in Autumn

Figure 6.

Poison Oak. Printed from Agriculture and Agri-Food Canada - www.agr.gc.ca

Figure 7.

Poison Sumac. Printed from Agriculture and Agri-Food Canada - www.agr.gc.ca

Removal of plants including the root systems, in areas frequented by children, is the best way to reduce the incidence of contact and allergic dermatitis. Vines should be severed at the root source and the roots removed if possible. Dried roots and leaves are still allergenic. Herbicides (amitrole, silvex, ammonium sulfamate, or 2,4-D acetic acid) can be used for control of large areas of poison ivy, oak, or sumac but are not species-specific and have the potential of killing surrounding plants or coming in contact with children or pets (Rietschel & Fowler, 2001a). Children and pets should not be in the area of application while the herbicide is still wet, and the herbicide should not be applied if there is any wind. The greatest danger of poisoning, however, occurs because of careless handling of gloves, shoes, clothing, or equipment used to apply the herbicide or because of unsafe storage or disposal of these chemicals (Rietschel & Fowler, 2001a).

When contact with poison ivy, oak, or sumac is anticipated, protective clothing (i.e., long sleeve shirts, long pants, socks and shoes) should be worn to cover arms and legs. The catechols in urushiol are soluble in rubber, therefore rubber gloves and rubber boots are not protective (Rietschel & Fowler, 2001a). Heavy-duty vinyl gloves are recommended when actively trying to remove these plants. Hands and skin that comes in contact with exterior surfaces of clothing with possible urushoil oil on it should be washed immediately with soap and water. If done immediately ACD can be prevented, but if even 10 minutes elapse with the oil on the skin only 50% will be removed (Fisher, 1996a). The oil residue on clothes, pets, garden and sports equipment, or toys can be removed with liberal soap and water washing.

Since skin area of contact often cannot be washed immediately with soap and water, attempts have been made to identify solvents or compounds that could be used hours after contact to leach the oil from the skin and prevent an allergic reaction. A study done by Stibich, Yagan, Sharma, Herndon, and Montgomery (2000) compared the effectiveness of three agents to prevent or reduce allergic reactivity in volunteers exposed to urushoil for 2-8 hours; Tecnu®, an over-the-counter product stated to "prevent/reduce poison ivy dermatitis up to eight hours post-exposure;" Goop®, an oil-removal product used to remove automobile grease; and Dial® Ultra, a commercial dishwashing soap. The study found 70%, 61.8%, and 56.4% effectiveness respectively in preventing erythema, vesiculation, and induration in positive responders to the allergen. Due to the small number of responders in the study (only 9 out of 20 volunteers) the differences in product effectiveness was not significant, but all did decrease the occurrence of allergic dermatitis. There was a significant cost difference between agents with Tecnu costing $1.25 per ounce, while Goop and Dial cost only $0.07 cents per ounce (Stibich et al., 2000). None of these compounds prevented ACD in all individuals; 30% of the study subjects developed a reaction in spite of washing the exposed skin areas.

Barrier preparations have been tried with varying success as a preventative measure when there is anticipated contact with poison ivy, oak, or sumac (i.e., hiking, camping, or working in areas with known Toxicodendron infestation) (Grevelink, Murrell, & Olsen, 1992). Marks and colleagues (1995) found that 144 test subjects with positive reactions to urushiol, if pretreated with a 5% quaternium-18 bentonite lotion, an organoclay substance commonly used in cosmetics, had absent or significantly reduced reactions (p < 0.0001). The mechanism of action is unknown, but 5% quaternium-18 bentonite lotion (Enviroderm Pharmaceuticals, trade name Ivy Block®) leaves a visible film on the skin and may interfere with absorption of urushoil by physically blocking skin contact. Ivy Block is the only FDA-approved preventive treatment for poison ivy, oak, and sumac ACD (www.enviroderm.com, 6-28-03).

There is no U.S. Food and Drug Administration approved and reliable oral regimen for desensitization to urushoil. Attempts have been made in the past to develop tolerance through oral ingestion of dilutions of poison ivy and poison oak extract, but these were unsuccessful in developing long-term tolerance and resulted in many side effects such as pruritus ani, hives, blisters, or dermatitis (Epstein, 1994; Tanner, 2000).

Topical Treatment for Lesions

Treatment for lesions caused by contact with poison ivy, oak, or sumac varies by the extent and severity of the lesions and the need for comfort or symptom relief. Treatment does not alter the duration of symptoms, however (Tanner, 2000). Topical lotions such as Calamine®, Ivy Rest®, Ivy Sooth®, can reduce itching and dry oozing lesions. The active ingredients in most topical lotions for ACD contain menthol, camphor, or phenol to sooth the skin and low potency hydrocortisone (Tanner, 2000). Topical antihistamines, benzocaine, and neomycin sulfate are no longer recommended because of possibility of sensitization to these agents (Williford & Sheretz, 1994). Tepid baths, oatmeal baths, cool compresses with astringents such as Burrow's® or Domeboro® can decrease pruritus. Aloe, calendula, Jewell Weed, and other emollients are frequently used herbal preparations that can be soothing to the skin, but no clinical trials are reported in the medical literature (Gardiner, Coles, & Kemper, 2001). Blisters can be opened to allow release of serum and enable topical preparations to have contact with the underlying skin. Caretakers should be reassured the fluid draining from the blister will not spread the lesions to other parts of the child's body or to other individuals. Occlusive dressings should not be used to cover lesions but a light gauze dressing can be used when lesions are weeping.

Topical glucocorticoids are frequently used, but low dose preparations are of little use in controlling symptoms and do not shorten the course of the condition. If less than 10% of the skin is involved, topical, moderate-to-high potency glucocorticoids once or twice a day are recommended except for use on the face or genitals, which should only be treated with low dose glucocorticoids (Lee & Arriola, 1999; Raimer, 2001; Tanner, 2000; Weston & Bruckner, 2000; Williford & Sheretz, 1994) (see Table 1 ). If high dose topical steroids are being used, abrupt discontinuation may result in rebound inflammation (Williford & Sheretz, 1994).

Systemic Treatment

For severe symptoms of allergic dermatitis caused by poison ivy, oak, or sumac, systemic medication may be necessary. Pruritus can be severe and many children cannot heed the directions to not scratch. Antihistamines given orally, especially at night, can be helpful in both mild and severe cases. Diphenhydramine (Benedryl®), chlorpheniramine (Chlor-Trimeton®), or hydroxyzine hydrochloride (Atarax®, Vistaril®) dosed by weight three to four times a day will help relieve itching (Brodell & Williams, 1999). Dosing this frequently can make the child drowsy and unable to function well in school, and the dosage may need to be decreased and topical soothing agents used liberally during the day. Dressing the child in cotton clothing that covers the lesions and keeping hands clean and fingernails short may help reduce secondary trauma to the skin.

If greater than 10% of the skin is affected, then systemic glucocorticoids are often used in conjunction with topical glucocorticoids, but individual assessment of the child for possible risks due to systemic steroid use must be made (Weston & Bruckner, 2000). The usual recommended treatment is prednisone 1 mg/kg/day as a single morning dose for 7-10 days followed by dose tapering for an additional 7-10 days (Bruckner & Weston, 2001). It is necessary to taper the prednisone over a 1-2 week period to avoid repeated flares of the lesions.

Occasionally, ACD will become secondarily infected requiring systemic antibiotics. The application of topical steroids or oral steroids may mask the signs of inflammation associated with secondary infection so lesions will need to be examined closely for indication of infection (i.e., pus verses translucent serum discharge, pain or tenderness, increasing inflammation and redness, increasing warmth, or fever). Research indicates multiple organisms can cause secondary infections with poison ivy, oak, and sumac so a broad-spectrum antibiotic that covers aerobic and anaerobic bacteria, such as amoxicillin/clavulanate, second generation cephalosporins, or azithromycin is recommended (Brook, 2002; Brook et al., 2000).


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