Cost-effective post-exposure prevention of poison ivy dermatitis

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.

Evaluation and Management of Toxicodendron Dermatitis in the Emergency Department: A Review of Current Practices

Toxicodendron dermatitis is an underappreciated disease seen in the emergency department. Although self-limiting, symptoms can be distressing and can last for weeks if untreated, particularly with re-exposure. Continuing research has improved our understanding of specific inflammatory markers that are associated with exposure to urushiol-the compound responsible for Toxicodendron dermatitis-although consensus for treatment remains varied and poorly supported. Owing to the lack of recent primary literature on the topic, many providers rely on historical precedent, expert opinion, and personal experience when treating this disease. This article provides a narrative review of the literature currently available on the effects of urushiol on key molecular and cellular functions and the prevention and treatment of Toxicodendron dermatitis.

Itchy Toxicodendron Plant Dermatitis

Plants such as the Toxicodendron species, consisting of poison ivy, poison oak, and poison sumac, largely contribute to allergic contact dermatitis with itch as a predominate symptom. Many individuals are affected by this skin condition, with approximately 50% to 70% of adults in North America demonstrating a degree of clinical sensitivity to this species of plants. In this review, we discuss the prevalence, pathophysiology, and clinical features of this contact dermatitis, as well as both treatment and prevention directed towards alleviation of itch. Updated research is emphasized throughout this review, although it is evident that this field is evolving, and more research is necessary to enhance treatment.

Efficacy of the saponin component of Impatiens capensis Meerb.in preventing urushiol-induced contact dermatitis

ETHNOPHARMACOLOGICAL RELEVANCE

Many different tribes of American Indians used jewelweed, Impatiens capensis Meerb, as a plant mash to reduce development of poison ivy dermatitis. Saponins are a natural soapy constituent found within plants. A 2012 study suggested that saponins may be present in jewelweed which could be responsible for its efficacy in preventing rash development following contact with Toxicodendron radicans (L.) Kuntze (poison ivy). This study validated this hypothesis and demonstrated additional biological activity of the jewelweed saponin containing extract.

MATERIALS AND METHODS

Fresh I. capensis leaves were extracted with methanol and further partitioned between ethyl acetate and water, with a final separation between water and n-butanol, to obtain a saponin containing extract. The presence of saponins in the extract was demonstrated by the observation of foaming and using a vanillin colorimetric assay for total saponins. Efficacy of the saponin containing extracts in rash reduction was tested by brushing poison ivy (PI) onto the forearms of volunteers (N=23) in six locations and treating these PI exposed areas with distilled water (control), saponin containing extracts, fresh plant mashes, and soaps made with and without plant extracts. Saponin containing extracts were further tested for biological activity against both gram negative and gram positive bacteria and against cancer cell lines A-375, HT-29, and MCF-7. Additionally, because saponins have been shown to have a stimulatory effect in cardiac muscle 2 µl saponin extract was applied superficially to black worms, Lumbriculus variegatus (N=5).

RESULTS, AND CONCLUSIONS

Both saponin containing extracts and all soaps tested were effective in reducing poison ivy dermatitis; thus, saponin content correlates with PI rash prevention. No apparent antibiosis was observed against any bacteria tested; however, dose response cytotoxicity was documented against MCF-7 breast cancer cells and cytostatic activity was seen against the HT-29 colon cancer cell lines. Lumbriculus variegatus exhibited a 138% increase in heart rate over baseline rate five minutes post treatment implying a possible positive chronotropic effect.

The effectiveness of jewelweed, Impatiens capensis, the related cultivar I. balsamina and the component, lawsone in preventing post poison ivy exposure contact dermatitis

ETHNOPHARMACOLOGICAL RELEVANCE

Impatiens capensis (jewelweed) is native to the Eastern and Midwestern US and Canada. Many Native American tribes used I. capensis and its close relatives to treat/prevent rash from plant sources particularly Toxicodendron radicans and Urtica dioica. I. balsamina (garden balsam) a native of China was used by the indigenous people of Asia for similar purposes.

AIM OF STUDY

This study aims to validate ethnopharmacological use of jewelweed in poison ivy (PI) dermatitis prevention and to refute scientific papers denying this efficacy. Additionally, the content of lawsone, the purported effective agent in jewelweed preparations, was measured to see if its concentration correlated with jewelweed preparation efficacy.

MATERIAL AND METHODS

Poison ivy was brushed onto forearms of volunteers in 6 locations and exposed areas were treated with jewelweed extracts, fresh plant mashes, soaps made of plant extracts, water and Dawn® dish soap. Rash development was scored on a scale of 0-14.

RESULTS

Jewelweed mash was effective in reducing poison ivy dermatitis, supporting ethnobotanical use. However, jewelweed extracts were not effective; and soaps made of these extracts were effective but no more so than jewelweed-free soaps. Lawsone content varied with harvest season and did not appear to affect rash development.

CONCLUSION

Jewelweed is an efficacious plant for preventing development of dermatitis following poison ivy contact, but soap is more effective. Lawsone content does not correlate with PI rash prevention. Perhaps saponins, the soapy component of jewelweed are the effective agents.