Poison Ivy

Scientific Name(s): Toxicodendron diversilobum (Torr. & A. Gray) Greene, Toxicodendron pubescens Mill., Toxicodendron radicans (L.) Kuntze, Toxicodendron rydbergii (Small ex Rydb.) Greene, Toxicodendron succedaneum (L.) Kuntze, Toxicodendron vernicifluum (Stokes) F.A. Barkley, Toxicodendron vernix (L.) Kuntze
Common Name(s): Chinese lacquer, Markweed, Poison dogwood, Poison elder, Poison ivy, Poison oak, Poison sumac

Medically reviewed by Drugs.com. Last updated on Oct 11, 2024.

Clinical Overview

Use

Quality clinical trials are lacking to support therapeutic applications.

Dosing

Poison ivy preparations should not be ingested due to potential for allergy and toxicity. Desensitization is not generally successful.

Contraindications

Not considered safe for use.

Pregnancy/Lactation

Avoid use. Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

None well documented.

Adverse Reactions

Contact dermatitis, including black-spot poison ivy dermatitis, is well recognized.

Toxicology

Clinical information is limited.

Botany

"Poison ivy" or "poison oak" refers to several members of the Toxicodendron genus (formerly Rhus), which grow throughout the United States. Identification of the exact species has traditionally relied on the adage "leaves of 3, let it be;" however, poison oak can have 3 to 5 leaflets and nonpoisonous sumac can have up to 13 leaflets. The nontoxic Virginia creeper (Parthenocissus quinquefolia) can also be mistaken for poison ivy.Gladman 2006, Parkinson 2002, USDA 2015

Images for identification are available on the US Department of Agriculture’s online PLANTS Database.USDA 2015 Generally, all species have U- or V-shaped leaf scars (where the leaf breaks from the stem), and flowers and fruits arise in the axillary position (the angle between the leaf and the branch). A black deposit is often present when Toxicodendron has been injured. Following trauma, the toxic oleoresin exudes, darkens with exposure to air, and hardens, which may assist in identification.Gladman 2006 Synonyms of T. pubescens include Rhus acutiloba, Rhus toxicarium, Rhus toxicodendron, Toxicodendron quercifolium, and Toxicodendron toxicarium.

Chemistry

An oily phenolic resin, termed "lobinol" by James B. McNair of the University of Chicago in the 1920s,(McNair 1921) is present in all poisonous Toxicodendron species and contains urushiol, a complex active principle derived from the Japanese term "sap." Urushiol is a mixture of antigenic catechols closely related to 3-n-pentadecylcatechol (3- PDC, hydrourushiol), varying in degree of saturation and length of side chain,(Duke 1992, Gladman 2006) and carried by resin canals in the bark, stem, leaflets, and certain flower parts. The relative percentages of 3-PDC and related catechols vary among the species and may be related to environmental conditions. The danger of toxicity is greatest in spring and summer when the sap is abundant, the urushiol content is high, and the plant is easily bruised.(Gladman 2006) Other chemical compounds in poison ivy include fisetin, gallotannic acid, kaempferol, myricetin, quercetin, rhamnose, and tannins.(Duke 1992) Additionally, heneicosandicarbonic, myristic, and palmitic acids have been identified in the fruit, and linoleic and oleic acids in the seeds.(Duke 1992)

The chemical composition of T. vernicifluum, and the lacquer sap/wax obtained from this species, is also under investigation, with polysaccharides, phenolic, and sesquiterpenoid compounds of interest.(Bai 2013, Chen 2014, He 2013, Jin 2015, Song 2010) A review of the chemical constituents of T. vernicifluum has been published.(Li 2021)

Uses and Pharmacology

A review of the potential pharmacological applications, based primarily on in vitro studies, has been published. Anti-inflammatory and antioxidant properties have been described, as well as cytotoxicity and antibacterial actions among others. Clinical studies are lacking.(Li 2021)

Arthritis/Inflammation

Animal data

Flavonoids extracted from the Chinese T. vernicifluum species have been investigated in vitro for anti-inflammatory activity against cyclo-oxygenase and antioxidant action.(Cho 2012, Kim 2015)

Anti-inflammatory activity has been described in rodent studies using homeopathic R. toxicodendron.(dos Santos 2007, Huh 2013, Lee 2016, Patel 2012, Patil 2009, Patil 2011) However, analytical documentation of the content and strength of the preparations used was not included.

Clinical data

A multicenter, randomized but unblinded trial (N = 142) evaluated the homeopathic preparation Disci/Rhus toxicodendron compositum (a composite medication authorized in Germany) in low back pain. The homeopathic injection preparation (51 patients) was not superior to placebo injections (P=0.35).(Pach 2011) A small clinical study (N=30), with some methodological limitations, reported superiority of a homeopathic complex over placebo when combined with physiotherapy for osteoarthritic pain. The homoeopathic complex contained Arnica montana 6CH, Bryonia alba 6CH, Causticum 6CH, Kalmia latifolia 6CH, Rhus toxicodendron 6CH and Calcarea fluorica 6CH.(Morris 2016)

Dosing

Clinical applications are lacking. Poison ivy preparations should not be ingested due to potential for allergy and toxicity.Duke 2002 Desensitization is not generally successful.Gladman 2006

Pregnancy / Lactation

Avoid use. Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

None well documented. A delayed hypersensitivity reaction (Rhus allergic contact dermatitis) occurred in a patient taking etanercept.Myers 2006

Adverse Reactions

Mild to severe allergic contact dermatitis, typically a pruritic, erythematous, and vesicular rash depending upon point of contact, is well documented. Black-spot poison ivy dermatitis has also been described, with characteristic black lesions.(Lehman 2020, McClanahan 2014, Pittman 2013)

Urushiol is degraded in water and immediate washing of the contact area with a detergent-containing or "grease-cutting" soap is advised.(Gladman 2006) Findings from a randomized clinical study suggest that long courses (15 days, with tapering) of oral corticosteroid treatment are more beneficial than short courses (5 days).(Curtis 2014) Contact dermatitis from homeopathic R. toxicodendron has been reported,(Cardinali 2004) as has dermatitis from ingestion of Rhus lacquer.(Park 2000) The oleoresin urushiol appears to be allergenic only to humans and higher primates. Desensitization is not generally successful.(Gladman 2006)

Toxicology

Dose-dependent genotoxicity has been observed in bone marrow of mice exposed to an extract of T. pubescens (Atlantic poison oak).Mersch-Sundermann 2004

Index Terms

Rhus acutiloba
Rhus toxicarium
Rhus toxicodendron
Toxicodendron quercifolium
Toxicodendron toxicarium

References

Disclaimer

This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this product. This information does not endorse this product as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this product. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this product. This information is not specific medical advice and does not replace information you receive from your health care provider. You should talk with your health care provider for complete information about the risks and benefits of using this product.

This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.

Bai Y, Yoshida T. Separation of lacquer polysaccharides and interaction with poly-L-lysine. Carbohydr Polym. 2013;98(1):270-275.23987344

Cardinali C, Francalanci S, Giomi B, Caproni M, Sertoli A, Fabbri P. Contact dermatitis from Rhus toxicodendron in a homeopathic remedy. J Am Acad Dermatol. 2004;50(1):150-151.14699391

Chen H, Wang C, Ye J, Zhou H, Lu L, Yang Z. Synthesis and properties of a lacquer wax-based quarternary ammonium gemini surfactant. Molecules. 2014;19(3):3596-3606.24662075

Cho N, Choi JH, Yang H, et al. Neuroprotective and anti-inflammatory effects of flavonoids isolated from Rhus verniciflua in neuronal HT22 and microglial BV2 cell lines. Food Chem Toxicol. 2012;50(6):1940-1945.22465834

Curtis G, Lewis AC. Treatment of severe poison ivy: a randomized, controlled trial of long versus short course oral prednisone. J Clin Med Res. 2014;6(6):429-434.25247016

dos Santos AL, Perazzo FF, Cardoso LG, Carvalho JC. In vivo study of the anti-inflammatory effect of Rhus toxicodendron. Homeopathy. 2007;96(2):95-101.17437936

Duke JA. Handbook of Biologically Active Phytochemicals and Their Activities. Boca Raton, FL: CRC Press Inc; 1992. http://www.ars-grin.gov/duke/. Accessed March 7, 2015.

Duke JA, Bogenschutz-Godwin M, duCellier J, Duke P. Handbook of Medicinal Herbs. 2nd ed. Boca Raton, FL: CRC Press; 2002.

Gladman AC. Toxicodendron dermatitis: poison ivy, oak, and sumac. Wilderness Environ Med. 2006;17(2):120-128.16805148

He JB, Luo J, Zhang L, Yan YM, Cheng YX. Sesquiterpenoids with new carbon skeletons from the resin of Toxicodendron vernicifluum as new types of extracellular matrix inhibitors. Org Lett. 2013;15(14):3602-3605.23815600

Huh YH, Kim MJ, Yeo MG. Homeopathic Rhus toxicodendron treatment increased the expression of cyclooxygenase-2 in primary cultured mouse chondrocytes. Homeopathy. 2013;102(4):248-253.24050770

Jin MJ, Kim IS, Park JS, Dong MS, Na CS, Yoo HH. Pharmacokinetic profile of eight phenolic compounds and their conjugated metabolites after oral administration of Rhus verniciflua extracts in rats. J Agric Food Chem. 2015;63(22):5410-5416.25998231

Kim KH, Moon E, Choi SU, Pang C, Kim SY, Lee KR. Identification of cytotoxic and anti-inflammatory constituents from the bark of Toxicodendron vernicifluum (Stokes) F.A. Barkley. J Ethnopharmacol. 2015;162:231-237.25582488

Lee KJ, Yeo MG. Homeopathic Rhus toxicodendron has dual effects on the inflammatory response in the mouse preosteoblastic cell line MC3T3-e1. Homeopathy. 2016;105(1):42-47.26827996

Lehman JS, Tollefson MM. Acquired beauty mark? New black macule on the face. Mayo Clin Proc. 2020;95(1):197-198. doi:10.1016/j.mayocp.2019.11.00131902415

Li MC, Zhang YQ, Meng CW, et al. Traditional uses, phytochemistry, and pharmacology of Toxicodendron vernicifluum (Stokes) F.A. Barkley - A review. J Ethnopharmacol. 2021;267:113476. doi:10.1016/j.jep.2020.11347633075438

McClanahan C, Asarch A, Swick BL. Black spot poison ivy. Int J Dermatol. 2014;53(6):752-753.24601999

McNair JB. Lobinol—a dermatitant from rhus diversiloba (poison oak). J Am Chem Soc. 1921;43(1):159-164.

Mersch-Sundermann V, Kassie F, Böhmer S, et al. Extract of Toxicodendron quercifolium caused genotoxicity and antigenotoxicity in bone marrow cells of CD1 mice. Food Chem Toxicol. 2004;42(10):1611-1617.15304307

Morris M, Pellow J, Solomon EM, Tsele-Tebakang T. Physiotherapy and a homeopathic complex for chronic low-back pain due to osteoarthritis: A randomized, controlled pilot study. Altern Ther Health Med. 2016;22(1):48-56.26773321

Myers W, Newman M, Katz B, Gottlieb AB. Ability to develop rhus allergic contact dermatitis in a patient with psoriasis receiving etanercept. J Am Acad Dermatol. 2006;55(5 suppl):S127-S128.17052536

Pach D, Brinkhaus B, Roll S, et al. Efficacy of injections with Disci/Rhus toxicodendron compositum for chronic low back pain–a randomized placebo-controlled trial. PLoS One. 2011;6(11):e26166.22087222

Park SD, Lee SW, Chun JH, Cha SH. Clinical features of 31 patients with systemic contact dermatitis due to the ingestion of Rhus (lacquer). Br J Dermatol. 2000;142(5):937-942.10809851

Parkinson G. Images in clinical medicine. The many faces of poison ivy. N Engl J Med. 2002;347(1):35.12097538

Patel DR, Ansari IA, Kachchhi YN, et al. Toxicodendron pubescens retains its anti-arthritic efficacy at 1M, 10M and CM homeopathic dilutions. Homeopathy. 2012;101(3):165-170.22818234

Patil CR, Gadekar AR, Patel PN, Rambhade A, Surana SJ, Gaushal MH. Dual effect of Toxicodendron pubescens on Carrageenan induced paw edema in rats. Homeopathy. 2009;98(2):88-91.19358961

Patil CR, Rambhade AD, Jadhav RB, et al. Modulation of arthritis in rats by Toxicodendron pubescens and its homeopathic dilutions. Homeopathy. 2011;100(3):131-137.21784329

Pittman MA, Lane DR. Black spot poison ivy: under the cover of darkness. J Emerg Med. 2013;44(4):e331-e332.23419214

Song DG, Lee JY, Lee EH, et al. Inhibitory effects of polyphenols isolated from Rhus verniciflua on Aldo-keto reductase family 1 B10. BMB Rep. 2010;43(4):268-272.20423612

Toxicodendron radicans. USDA, NRCS. 2015 The PLANTS Database (http://plants.usda.gov/, March 2015). National Plant Data Center, Baton Rouge, LA 70874-4490 USA. Accessed April 18, 2015.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer