Several barrier creams are commercially available to help prevent absorption or to deactivate the urushiol antigen. These products are used widely by forestry workers and wildland firefighters.23 One such barrier cream is bentoquatam (sold as various trade names), an organoclay compound made of quaternium-18 bentonite that interferes with absorption of the allergen by acting as a physical blocker.24
Treatment
After Toxicodendron dermatitis develops, several treatments are available to help manage symptoms. Calamine lotion can be used to help dry weeping lesions.25,26 Topical steroids can be used to help control pruritus and alleviate inflammation. High-potency topical corticosteroids such as clobetasol and mid-potency steroids such as triamcinolone can be used. Topical anesthetics (eg, benzocaine, pramoxine, benzyl alcohol) might provide symptomatic relief.27,28
Oral antihistamines can allow for better sleep by providing sedation but do not target the pruritus of poison ivy dermatitis, which is not histamine mediated.29,30 Systemic corticosteroids usually are considered in more severe dermatitis—when 20% or more of the body surface area is involved; blistering and itching are severe; or the face, hands, or genitalia are involved.31,32
Clinical Uses
Therapeutic uses for poison ivy have been explored extensively. In 1892, Dakin33 reported that ingestion of leaves by Native Americans reduced the incidence and severity of skin lesions after contact with poison ivy. Consumption of poison ivy was further studied by Epstein and colleagues34 in 1974; they concluded that ingestion of a large amount of urushiol over a period of 3 months or longer may help with hyposensitization—but not complete desensitization—to contact with poison ivy. However, the risk for adverse effects is thought to outweigh benefits because ingestion can cause perianal dermatitis, mucocutaneous sequelae, and systemic contact dermatitis.2
Although the use of Toxicodendron plants in modern-day medicine is limited, development of a vaccine (immunotherapy) against Toxicodendron dermatitis offers an exciting opportunity for further research.