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Urushiol

January 20, 2023

Urushiol /ʊˈruːʃi.ɒl/ is an oily mixture of organic compounds with allergenic properties found in plants of the family Anacardiaceae, especially Toxicodendron spp. (e.g., poison oak, Chinese lacquer tree, poison ivy, poison sumac), Comocladia spp. (maidenplums), Metopium spp. (poisonwood), and also in parts of the mango tree as well as the fruit of the cashew tree.[1][2][3][4][5][6] In most individuals, urushiol causes an allergic skin rash on contact,[7] known as urushiol-induced contact dermatitis.

Urushiol
R = (CH2)14CH3, (CH2)7CH=CH(CH2)5CH3, (CH2)7CH=CHCH2CH=CH(CH2)2CH3, (CH2)7CH=CHCH2CH=CHCH=CHCH3, (CH2)7CH=CHCH2CH=CHCH2CH=CH2 and more.

The name urushiol is derived from the Japanese word for the lacquer tree, Toxicodendron vernicifluum (漆, urushi).[8] The oxidation and polymerization of urushiol in the tree's sap in the presence of moisture allows it to form a hard lacquer, which is used to produce traditional Chinese, Korean and Japanese lacquerware.

History

Although urushiol-containing lacquers and their skin-irritating properties were well known in East Asia for several millennia, its first recorded Western texts were in 1624 by John Smith and he initially likened poison ivy to English Ivy.[9] He did not classify it as a poison at first due to the speed with which its rash disappeared and Smith hypothesized that there may actually be medicinal uses for the plant.[9] In the 18th and 19th centuries, many experiments were done in this area to determine whether or not this theory was true. Because that era's medicinal culture was dominated by plant-based treatments, physicians were hopeful that the strong effect this chemical produced on the body could be effective in some way. André-Ignace-Joseph Dufresnoy was one of the first to come up with a medicinal use for this chemical in 1780 when he boiled poison ivy to produce an infusion for internal use.[9] This led to a distilled extract of poison ivy which he prescribed to many people suffering from skin problems and even paralysis. He claimed this treatment to have yielded several positive results.[9]

For many years, poison ivy was thought to fall into the Rhus genus; however, in the 1900s, it was reclassified into a more appropriate genus, Toxicodendron, meaning poison tree.[9] There were many documented cases of irritations and allergic reactions from the plant, and its prevalence in medicinal use quickly dwindled. After this new categorization, scientists began attempts to determine what it was that rendered plants of this genus noxious, starting with a hypothesis of a volatile oil present in the plants.[9] While this proved incorrect, Rikou Majima from Japan was able to determine that the chemical urushiol was the irritant. Further, he determined that the substance was a type of alkyl catechol, and due to its structure it was able to penetrate the skin and survive on surfaces for months to years.[9] Urushiol's ability to polymerise into a hard glossy coating is the chemical basis for traditional lacquerware in many Asian countries.[10] After urushiol comes in contact with oxygen, under certain conditions it becomes a black lacquer and has been named urushi lacquer.[11]

Characteristics

Urushiol in its pure form is a pale-yellow liquid with a specific gravity of 0.968 and a boiling point of 200 °C (392 °F). It is soluble in diethyl ether, acetone, ethanol, carbon tetrachloride, and benzene.[12][13]

Urushiol is a mixture of several closely related organic compounds. Each consists of a catechol substituted in the 3 position with a hydrocarbon chain that has 15 or 17 carbon atoms. The hydrocarbon group may be saturated or unsaturated. The exact composition of the mixture varies, depending on the plant source. Whereas western poison oak urushiol contains chiefly catechols with C17 side-chains,[14] poison ivy and poison sumac contain mostly catechols with C15 sidechains.

The likelihood and severity of allergic reaction to urushiol is dependent on the degree of unsaturation of the hydrocarbon chain. Less than half of the general population experience a reaction with the saturated urushiol alone, but over 90% do so with urushiol that contains at least two degrees of unsaturation (double bonds). Longer side chains tend to produce a stronger reaction.[15]

Urushiol is an oleoresin contained within the sap of poison ivy and related plants, and after injury to the plant, or late in the fall, the sap leaks to the surface of the plant, where under certain temperature and humidity conditions the urushiol becomes a blackish lacquer after being in contact with oxygen.[15][16][11] Urushi lacquer is very stable. It is able to withstand disturbances from alkali, acid, and alcohol, while also being able to resist temperatures of over 300 °C. However, the lacquer can be degraded by UV rays from the sun and other sources.[10]

Within the United States, urushiol-containing plants are distributed throughout. Poison ivy can be found in all states except California, Alaska, and Hawaii. Poison Oak can be found on the west coast or some states in the southeast, while poison sumac can be found only in the eastern half of the country.[17]

These plants all have distinguishing features that will help in identification. Poison ivy always grows with three shiny, pointy leaves. Poison oak has a similar look, but with larger and more rounded leaves that are hairy and grow in groups of 3, 5, or 7. Poison sumac grows in groups of 7 to 13 leaves, but always in an odd number. The leaves are feather-shaped and shiny.[18]

Allergic response and treatment

Before the urushiol has been absorbed by the skin, it can be removed with soap and water. Substantial amounts of urushiol may be absorbed within minutes. Once urushiol has penetrated the skin, attempting to remove it with water is ineffective.[15] After being absorbed by the skin, it is recognized by the immune system's dendritic cells, otherwise called Langerhans cells. These cells then migrate to the lymph nodes, where they present the urushiol to T-lymphocytes and thus recruit them to the skin, and the T-lymphocytes cause pathology through the production of cytokines and cytotoxic damage to the skin.[19] This causes the painful rash, blisters, and itching.

Once this response starts, only a few treatments, such as cortisone or prednisone, are effective.[9] Medications that can reduce the irritation include antihistamines (diphenhydramine (Benadryl) or cetirizine (Zyrtec)). Other treatments include applying cold water or calamine lotion to soothe the pain and stop the itching.[9]

Mechanism of action

A video describing the mechanism of action for poison ivy and other such plants containing urushiol
Main article: Urushiol-induced contact dermatitis

To cause an allergic dermatitis reaction, the urushiol is first oxidized to create two double-bonded oxygens on the chemical. It then reacts with a protein nucleophile to trigger a reaction within the skin. Dermatitis is mediated by an induced immune response. Urushiol is too small a molecule to directly activate an immune response. Instead, it attaches to certain proteins of the skin, where it acts as a hapten, leading to a type IV hypersensitive reaction.[20][self-published source?][21]

Hydrocortisone, the active ingredient in cortisone, works to alleviate this condition by stopping the release of chemicals that cause the dermatitis reaction.[22] Hydrocortisone itself does not react with urushiol in any way.

 
Basic mechanism of Urushiol causing allergic dermatitis

See also

References

  1. ^ Cruse, Julius M.; Lewis, Robert E. (2003). Atlas of Immunology, Second Edition. CRC Press. p. 375. ISBN 978-1-4200-3994-8.
  2. ^ "Can Reaction to Poison Ivy Cause Mango Allergy?". American College of Allergy, Asthma and Immunology. Retrieved 2014-06-02.
  3. ^ . NIH. Archived from the original on 2019-12-09. Retrieved 2014-06-02.
  4. ^ Rietschel, Robert L.; Fowler, Joseph F.; Fisher, Alexander A. (2008). Fisher's Contact Dermatitis. PMPH-USA. p. 407. ISBN 978-1-55009-378-0.
  5. ^ Appleby, Maia (Aug 2013). "Mango & Skin Rashes". Livestrong. Retrieved 2014-06-02.
  6. ^ Aguilar-Ortigoza, Carlos J.; Sosa, Victoria; Aguilar-Ortigoza, Marcial (2003-09-01). "Toxic Phenols in various Anacardiaceae species". Economic Botany. 57 (3): 354. doi:10.1663/0013-0001(2003)057[0354:TPIVAS]2.0.CO;2. ISSN 1874-9364. S2CID 41808640.
  7. ^ Tilton, Buck (2004). Wilderness First Responder: How to Recognize, Treat, and Prevent Emergencies in the Backcountry. Globe Pequot. ISBN 978-0-7627-2801-5.
  8. ^ Oxford English Dictionary[full citation needed]
  9. ^ a b c d e f g h i "No Ill Nature: The Surprising History and Science of Poison Ivy and Its Relatives". Science History Institute. 2013-06-02. Retrieved 2020-04-22.
  10. ^ a b Arney, Kat (13 June 2017). "Urushiol". Education in Chemistry. Vol. 54, no. 4. Royal Society of Chemistry. p. 8. Retrieved 19 June 2018.
  11. ^ a b Barceloux, Donald G. (2008). Medical Toxicology of Natural Substances: Foods, Fungi, Medicinal Herbs, Plants, and Venomous Animals. John Wiley and Sons. pp. 681–. ISBN 978-0-471-72761-3. Retrieved 2010-07-26.
  12. ^ Hawley's Condensed Chemical Dictionary (14th ed.). John Wiley & Sons. 2002.
  13. ^ Howell, J. B. (1 October 1941). "Solubility of the Dermatitis-Producing Fraction of Poison Ivy". Archives of Dermatology. 44 (4): 665. doi:10.1001/archderm.1941.01500040120010.
  14. ^ Hogan, C. Michael (2008). Stromberg, Nicklas (ed.). . GlobalTwitcher. Archived from the original on 2009-07-21. Retrieved 2009-07-21.
  15. ^ a b c McGovern, Thomas; Barkley, Theodore (1998). "Botanical Dermatology". International Journal of Dermatology. 37 (5): 321–334. doi:10.1046/j.1365-4362.1998.00385.x. PMID 9620476. S2CID 221810453.
  16. ^ Rietschel, Robert L.; Fowler, Joseph F.; Fisher, Alexander A. (2008). Fisher's Contact Dermatitis. PMPH-USA. p. 408. ISBN 978-1-55009-378-0. Retrieved 2010-07-26.
  17. ^ "Poisonous Plants – Geographic Distribution | NIOSH | CDC". www.cdc.gov. 2020-02-21. Retrieved 2020-04-27.
  18. ^ "Slideshow: Images of Poison Ivy, Poison Oak, Poison Sumac". WebMD. Retrieved 2020-04-27.
  19. ^ Gober, D. Michael; et al. (2008). "Human Natural Killer T Cells infiltrate into the Skin at Elicitation Sites of Allergic Contact Dermatitis". Journal of Investigative Dermatology. 128 (6): 1460–1469. doi:10.1038/sj.jid.5701199. PMC 3125127. PMID 18079745.
  20. ^ "Forget 'Polytetrafluoroethene', Pentadecacatechol is where it's at". 2012-07-11. Retrieved 2014-09-22.
  21. ^ Marwa, K; Kondamudi, NP (2021-01-01). "Type IV Hypersensitivity Reaction". StatPearls. Treasure Island (FL): StatPearls Publishing. PMID 32965899. Retrieved 2021-11-28.
  22. ^ "Hydrocortisone cream: a steroid medicine". nhs.uk. 2019-01-17. Retrieved 2020-04-27.

Further reading

  • Grevelink, Suzanne A.; Murrell, Dédée F.; Olsen, Elise A. (August 1992). "Effectiveness of various barrier preparations in preventing and/or ameliorating experimentally produced Toxicodendron dermatitis". Journal of the American Academy of Dermatology. 27 (2): 182–188. doi:10.1016/0190-9622(92)70167-e. PMID 1430354.
  • Symes, William F.; Dawson, Charles R. (June 1954). "Poison Ivy 'Urushiol'". Journal of the American Chemical Society. 76 (11): 2959–2963. doi:10.1021/ja01640a030.
  • Xu, Hongli; Lu, Zaijun; Zhang, Guangzhao (2012). "Synthesis and properties of thermosetting resin based on urushiol". RSC Advances. 2 (7): 2768. Bibcode:2012RSCAd...2.2768X. doi:10.1039/C2RA00829G.
  • Kalish, RS; Johnson, KL (1 December 1990). "Enrichment and function of urushiol (poison ivy)-specific T lymphocytes in lesions of allergic contact dermatitis to urushiol". Journal of Immunology. 145 (11): 3706–3713. PMID 2147199. INIST:4566503 NAID 80005581100.
  • Xia, Jianrong; Xu, Yanlian; Lin, Jinhuo; Hu, Binghuan (January 2008). "UV-induced polymerization of urushiol without photoinitiator". Progress in Organic Coatings. 61 (1): 7–10. doi:10.1016/j.porgcoat.2007.08.007.
  • Epstein, William L. (1 March 1974). "Poison Oak Hyposensitization: Evaluation of Purified Urushiol". Archives of Dermatology. 109 (3): 356–360. doi:10.1001/archderm.1974.01630030016002. PMID 4273614.
  • Je, Hyeondoo; Won, Jongok (January 2021). "Natural urushiol as a novel under-water adhesive". Chemical Engineering Journal. 404: 126424. doi:10.1016/j.cej.2020.126424. S2CID 224932889.
  • Oshima, Ryuichi; Yamauchi, Yoshio; Watanabe, Chuichi; Kumanotani, Ju (July 1985). "Enzymic oxidative coupling of urushiol in sap of the lac tree, Rhus vernicifera". The Journal of Organic Chemistry. 50 (15): 2613–2621. doi:10.1021/jo00215a002.

External links

  • Poison Oak 2015-10-06 at the Wayback Machine at Wayne's Word
  • Reduce poison ivy dermatitis with the following steps – Deseret News
  • The Poison Ivy Tutorial

January 20, 2023
urushiol, oily, mixture, organic, compounds, with, allergenic, properties, found, plants, family, anacardiaceae, especially, toxicodendron, poison, chinese, lacquer, tree, poison, poison, sumac, comocladia, maidenplums, metopium, poisonwood, also, parts, mango. Urushiol ʊ ˈ r uː ʃ i ɒ l is an oily mixture of organic compounds with allergenic properties found in plants of the family Anacardiaceae especially Toxicodendron spp e g poison oak Chinese lacquer tree poison ivy poison sumac Comocladia spp maidenplums Metopium spp poisonwood and also in parts of the mango tree as well as the fruit of the cashew tree 1 2 3 4 5 6 In most individuals urushiol causes an allergic skin rash on contact 7 known as urushiol induced contact dermatitis UrushiolR CH2 14CH3 CH2 7CH CH CH2 5CH3 CH2 7CH CHCH2CH CH CH2 2CH3 CH2 7CH CHCH2CH CHCH CHCH3 CH2 7CH CHCH2CH CHCH2CH CH2 and more The name urushiol is derived from the Japanese word for the lacquer tree Toxicodendron vernicifluum 漆 urushi 8 The oxidation and polymerization of urushiol in the tree s sap in the presence of moisture allows it to form a hard lacquer which is used to produce traditional Chinese Korean and Japanese lacquerware Contents 1 History 2 Characteristics 3 Allergic response and treatment 4 Mechanism of action 5 See also 6 References 7 Further reading 8 External linksHistory EditAlthough urushiol containing lacquers and their skin irritating properties were well known in East Asia for several millennia its first recorded Western texts were in 1624 by John Smith and he initially likened poison ivy to English Ivy 9 He did not classify it as a poison at first due to the speed with which its rash disappeared and Smith hypothesized that there may actually be medicinal uses for the plant 9 In the 18th and 19th centuries many experiments were done in this area to determine whether or not this theory was true Because that era s medicinal culture was dominated by plant based treatments physicians were hopeful that the strong effect this chemical produced on the body could be effective in some way Andre Ignace Joseph Dufresnoy was one of the first to come up with a medicinal use for this chemical in 1780 when he boiled poison ivy to produce an infusion for internal use 9 This led to a distilled extract of poison ivy which he prescribed to many people suffering from skin problems and even paralysis He claimed this treatment to have yielded several positive results 9 For many years poison ivy was thought to fall into the Rhus genus however in the 1900s it was reclassified into a more appropriate genus Toxicodendron meaning poison tree 9 There were many documented cases of irritations and allergic reactions from the plant and its prevalence in medicinal use quickly dwindled After this new categorization scientists began attempts to determine what it was that rendered plants of this genus noxious starting with a hypothesis of a volatile oil present in the plants 9 While this proved incorrect Rikou Majima from Japan was able to determine that the chemical urushiol was the irritant Further he determined that the substance was a type of alkyl catechol and due to its structure it was able to penetrate the skin and survive on surfaces for months to years 9 Urushiol s ability to polymerise into a hard glossy coating is the chemical basis for traditional lacquerware in many Asian countries 10 After urushiol comes in contact with oxygen under certain conditions it becomes a black lacquer and has been named urushi lacquer 11 Characteristics EditUrushiol in its pure form is a pale yellow liquid with a specific gravity of 0 968 and a boiling point of 200 C 392 F It is soluble in diethyl ether acetone ethanol carbon tetrachloride and benzene 12 13 Urushiol is a mixture of several closely related organic compounds Each consists of a catechol substituted in the 3 position with a hydrocarbon chain that has 15 or 17 carbon atoms The hydrocarbon group may be saturated or unsaturated The exact composition of the mixture varies depending on the plant source Whereas western poison oak urushiol contains chiefly catechols with C17 side chains 14 poison ivy and poison sumac contain mostly catechols with C15 sidechains The likelihood and severity of allergic reaction to urushiol is dependent on the degree of unsaturation of the hydrocarbon chain Less than half of the general population experience a reaction with the saturated urushiol alone but over 90 do so with urushiol that contains at least two degrees of unsaturation double bonds Longer side chains tend to produce a stronger reaction 15 Urushiol is an oleoresin contained within the sap of poison ivy and related plants and after injury to the plant or late in the fall the sap leaks to the surface of the plant where under certain temperature and humidity conditions the urushiol becomes a blackish lacquer after being in contact with oxygen 15 16 11 Urushi lacquer is very stable It is able to withstand disturbances from alkali acid and alcohol while also being able to resist temperatures of over 300 C However the lacquer can be degraded by UV rays from the sun and other sources 10 Within the United States urushiol containing plants are distributed throughout Poison ivy can be found in all states except California Alaska and Hawaii Poison Oak can be found on the west coast or some states in the southeast while poison sumac can be found only in the eastern half of the country 17 These plants all have distinguishing features that will help in identification Poison ivy always grows with three shiny pointy leaves Poison oak has a similar look but with larger and more rounded leaves that are hairy and grow in groups of 3 5 or 7 Poison sumac grows in groups of 7 to 13 leaves but always in an odd number The leaves are feather shaped and shiny 18 Allergic response and treatment EditThis section needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Urushiol news newspapers books scholar JSTOR July 2021 Learn how and when to remove this template message Before the urushiol has been absorbed by the skin it can be removed with soap and water Substantial amounts of urushiol may be absorbed within minutes Once urushiol has penetrated the skin attempting to remove it with water is ineffective 15 After being absorbed by the skin it is recognized by the immune system s dendritic cells otherwise called Langerhans cells These cells then migrate to the lymph nodes where they present the urushiol to T lymphocytes and thus recruit them to the skin and the T lymphocytes cause pathology through the production of cytokines and cytotoxic damage to the skin 19 This causes the painful rash blisters and itching Once this response starts only a few treatments such as cortisone or prednisone are effective 9 Medications that can reduce the irritation include antihistamines diphenhydramine Benadryl or cetirizine Zyrtec Other treatments include applying cold water or calamine lotion to soothe the pain and stop the itching 9 Mechanism of action Edit source source source source source source source source source source source source source source track A video describing the mechanism of action for poison ivy and other such plants containing urushiol Main article Urushiol induced contact dermatitis To cause an allergic dermatitis reaction the urushiol is first oxidized to create two double bonded oxygens on the chemical It then reacts with a protein nucleophile to trigger a reaction within the skin Dermatitis is mediated by an induced immune response Urushiol is too small a molecule to directly activate an immune response Instead it attaches to certain proteins of the skin where it acts as a hapten leading to a type IV hypersensitive reaction 20 self published source 21 Hydrocortisone the active ingredient in cortisone works to alleviate this condition by stopping the release of chemicals that cause the dermatitis reaction 22 Hydrocortisone itself does not react with urushiol in any way Basic mechanism of Urushiol causing allergic dermatitisSee also EditAnti itch drugs for treating the toxin Bentoquatam a barrier cream applied before exposure Burow s solution which can treat the symptoms of the rash caused by urushiol Ginkgo biloba and cashew plants containing chemicals closely related to urushiol Hapten small molecules that can elicit an immune response under certain conditions Mango trees which may cause cross reaction allergies with urushiol References Edit Cruse Julius M Lewis Robert E 2003 Atlas of Immunology Second Edition CRC Press p 375 ISBN 978 1 4200 3994 8 Can Reaction to Poison Ivy Cause Mango Allergy American College of Allergy Asthma and Immunology Retrieved 2014 06 02 Urushiol Human Health Effects NIH Archived from the original on 2019 12 09 Retrieved 2014 06 02 Rietschel Robert L Fowler Joseph F Fisher Alexander A 2008 Fisher s Contact Dermatitis PMPH USA p 407 ISBN 978 1 55009 378 0 Appleby Maia Aug 2013 Mango amp Skin Rashes Livestrong Retrieved 2014 06 02 Aguilar Ortigoza Carlos J Sosa Victoria Aguilar Ortigoza Marcial 2003 09 01 Toxic Phenols in various Anacardiaceae species Economic Botany 57 3 354 doi 10 1663 0013 0001 2003 057 0354 TPIVAS 2 0 CO 2 ISSN 1874 9364 S2CID 41808640 Tilton Buck 2004 Wilderness First Responder How to Recognize Treat and Prevent Emergencies in the Backcountry Globe Pequot ISBN 978 0 7627 2801 5 Oxford English Dictionary full citation needed a b c d e f g h i No Ill Nature The Surprising History and Science of Poison Ivy and Its Relatives Science History Institute 2013 06 02 Retrieved 2020 04 22 a b Arney Kat 13 June 2017 Urushiol Education in Chemistry Vol 54 no 4 Royal Society of Chemistry p 8 Retrieved 19 June 2018 a b Barceloux Donald G 2008 Medical Toxicology of Natural Substances Foods Fungi Medicinal Herbs Plants and Venomous Animals John Wiley and Sons pp 681 ISBN 978 0 471 72761 3 Retrieved 2010 07 26 Hawley s Condensed Chemical Dictionary 14th ed John Wiley amp Sons 2002 Howell J B 1 October 1941 Solubility of the Dermatitis Producing Fraction of Poison Ivy Archives of Dermatology 44 4 665 doi 10 1001 archderm 1941 01500040120010 Hogan C Michael 2008 Stromberg Nicklas ed Western poison oak Toxicodendron diversilobum GlobalTwitcher Archived from the original on 2009 07 21 Retrieved 2009 07 21 a b c McGovern Thomas Barkley Theodore 1998 Botanical Dermatology International Journal of Dermatology 37 5 321 334 doi 10 1046 j 1365 4362 1998 00385 x PMID 9620476 S2CID 221810453 Rietschel Robert L Fowler Joseph F Fisher Alexander A 2008 Fisher s Contact Dermatitis PMPH USA p 408 ISBN 978 1 55009 378 0 Retrieved 2010 07 26 Poisonous Plants Geographic Distribution NIOSH CDC www cdc gov 2020 02 21 Retrieved 2020 04 27 Slideshow Images of Poison Ivy Poison Oak Poison Sumac WebMD Retrieved 2020 04 27 Gober D Michael et al 2008 Human Natural Killer T Cells infiltrate into the Skin at Elicitation Sites of Allergic Contact Dermatitis Journal of Investigative Dermatology 128 6 1460 1469 doi 10 1038 sj jid 5701199 PMC 3125127 PMID 18079745 Forget Polytetrafluoroethene Pentadecacatechol is where it s at 2012 07 11 Retrieved 2014 09 22 Marwa K Kondamudi NP 2021 01 01 Type IV Hypersensitivity Reaction StatPearls Treasure Island FL StatPearls Publishing PMID 32965899 Retrieved 2021 11 28 Hydrocortisone cream a steroid medicine nhs uk 2019 01 17 Retrieved 2020 04 27 Further reading EditGrevelink Suzanne A Murrell Dedee F Olsen Elise A August 1992 Effectiveness of various barrier preparations in preventing and or ameliorating experimentally produced Toxicodendron dermatitis Journal of the American Academy of Dermatology 27 2 182 188 doi 10 1016 0190 9622 92 70167 e PMID 1430354 Symes William F Dawson Charles R June 1954 Poison Ivy Urushiol Journal of the American Chemical Society 76 11 2959 2963 doi 10 1021 ja01640a030 Xu Hongli Lu Zaijun Zhang Guangzhao 2012 Synthesis and properties of thermosetting resin based on urushiol RSC Advances 2 7 2768 Bibcode 2012RSCAd 2 2768X doi 10 1039 C2RA00829G Kalish RS Johnson KL 1 December 1990 Enrichment and function of urushiol poison ivy specific T lymphocytes in lesions of allergic contact dermatitis to urushiol Journal of Immunology 145 11 3706 3713 PMID 2147199 INIST 4566503 NAID 80005581100 Xia Jianrong Xu Yanlian Lin Jinhuo Hu Binghuan January 2008 UV induced polymerization of urushiol without photoinitiator Progress in Organic Coatings 61 1 7 10 doi 10 1016 j porgcoat 2007 08 007 Epstein William L 1 March 1974 Poison Oak Hyposensitization Evaluation of Purified Urushiol Archives of Dermatology 109 3 356 360 doi 10 1001 archderm 1974 01630030016002 PMID 4273614 Je Hyeondoo Won Jongok January 2021 Natural urushiol as a novel under water adhesive Chemical Engineering Journal 404 126424 doi 10 1016 j cej 2020 126424 S2CID 224932889 Oshima Ryuichi Yamauchi Yoshio Watanabe Chuichi Kumanotani Ju July 1985 Enzymic oxidative coupling of urushiol in sap of the lac tree Rhus vernicifera The Journal of Organic Chemistry 50 15 2613 2621 doi 10 1021 jo00215a002 External links EditPoison Oak Archived 2015 10 06 at the Wayback Machine at Wayne s Word Reduce poison ivy dermatitis with the following steps Deseret News The Poison Ivy Tutorial Retrieved from https en wikipedia org w index php title Urushiol amp oldid 1118066904, wikipedia, wiki, book, books, library,

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