Toxicodendron radicans

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Toxicodendron radicans
2014-10-29 13 43 39 Poison Ivy foliage during autumn leaf coloration in Ewing, New Jersey.JPG
Poison ivy during autumn
Toxicodendron radicans, leaves.jpg
Poison ivy in spring, Ottawa, Ontario
Status TNC G5.svg
Secure  (NatureServe) [2]
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Sapindales
Family: Anacardiaceae
Genus: Toxicodendron
Species:
T. radicans
Binomial name
Toxicodendron radicans
(L.) Kuntze
Eastern Poison Ivy Range.png
Toxicodendron radicans range map in the United States and Canada
Synonyms
  • Rhus radicansL.
  • Rhus verrucosaScheele, syn of subsp. verrucosum

Toxicodendron radicans, commonly known as eastern poison ivy [3] or poison ivy, is an allergenic flowering plant that occurs in Asia and eastern North America. The species is well known for causing urushiol-induced contact dermatitis, an itchy, irritating, and sometimes painful rash, in most people who touch it. The rash is caused by urushiol, a clear liquid compound in the plant's sap. [4] The species is variable in its appearance and habit, and despite its common name, it is not a true ivy ( Hedera ), but rather a member of the cashew and pistachio family (Anacardiaceae). T. radicans is commonly eaten by many animals and the seeds are consumed by birds, [5] but poison ivy is most often thought of as an unwelcome weed. It is a different species from western poison ivy, T. rydbergii , which has similar effects.

Contents

Description

Numerous subspecies and/or varieties of T. radicans are known. [6] They can be found growing in any of the following forms, all having woody stems:

The deciduous leaves of T. radicans are trifoliate with three almond-shaped leaflets. [7] Leaf color ranges from light green (usually the younger leaves) to dark green (mature leaves), turning bright red in fall; though other sources say leaves are reddish when expanding, turn green through maturity, then back to red, orange, or yellow in the fall. The leaflets of mature leaves are somewhat shiny. The leaflets are 3–12 cm (1+1⁄4–4+3⁄4 in) long, rarely up to 30 cm (12 in). Each leaflet has a few or no teeth along its edge, and the leaf surface is smooth. Leaflet clusters are alternate on the vine, and the plant has no thorns. Vines growing on the trunk of a tree become firmly attached through numerous aerial rootlets. [8] The vines develop adventitious roots, or the plant can spread from rhizomes or root crowns. The milky sap of poison ivy darkens after exposure to the air.

T. radicans spreads either vegetatively or sexually. It is dioecious; flowering occurs from May to July. The yellowish- or greenish-white flowers are typically inconspicuous and are located in clusters up to 8 cm (3 in) above the leaves. The berry-like fruit, a drupe, mature by August to November with a grayish-white colour. [7]

Identification

These four characteristics are sufficient to identify poison ivy in most situations: (a) clusters of three leaflets, (b) alternate leaf arrangement, (c) lack of thorns, and (d) each group of three leaflets grows on its own stem, which connects to the main vine, the middle stem is longer. [9] The appearance of poison ivy can vary greatly among environments, and even within a large area. Identification by experienced people is often made difficult by leaf damage, the plant's leafless condition during winter, and unusual growth forms due to environmental or genetic factors. Various mnemonic rhymes describe the characteristic appearance of poison ivy: [10]

  1. "Leaves of three, let it be" is the best known and most useful cautionary rhyme. It applies to poison oak, as well as to poison ivy. However, some other innocuous plants have similar leaves. [11]
  2. "Hairy vine, no friend of mine" [12]
  3. "Berries white, run in fright" and "Berries white, danger in sight" [12]

Similar-looking plants

  • Box elder ( Acer negundo ) saplings have leaves that can look very similar to those of poison ivy, although the symmetry of the plant itself is very different. While box elders often have five or seven leaflets, three leaflets are also common, especially on smaller saplings. The two can be differentiated by observing the placement of the leaves where the leaf stalk meets the main branch (where the three leaflets are attached). Poison ivy has alternate leaves, which means the three-leaflet leaves alternate along the main branch. Boxelder has opposite leaves; another leaf stalk directly on the opposite side is characteristic of box elder.
  • Virgin's bower ( Clematis virginiana ) is a vine of the buttercup family native to eastern North America. This vine can climb up to 10–20 feet (3.0–6.1 m) tall. It grows on the edges of the woods, moist slopes, and fence rows, and in thickets and streambanks. It produces white, fragrant flowers about 1 inch (2.5 cm) in diameter between July and September.
  • Virginia creeper ( Parthenocissus quinquefolia ) vines can look like poison ivy. The younger leaves can consist of three leaflets but have a few more serrations along the leaf edge, and the leaf surface is somewhat wrinkled. However, most Virginia creeper leaves have five leaflets. Virginia creeper and poison ivy very often grow together, even on the same tree. Even those who do not get an allergic reaction to poison ivy may be allergic to the oxalate crystals in Virginia creeper sap.
  • Western poison oak ( Toxicodendron diversilobum ) leaflets also grow in threes on the end of a stem, but each leaflet is shaped somewhat like an oak leaf. Western poison oak grows only in western North America, although many people refer to poison ivy as poison oak, because poison ivy grows in either the ivy-like form or the brushy oak-like form depending on the moisture and brightness of its environment. The ivy form likes shady areas with only a little sun, tends to climb the trunks of trees, and can spread rapidly along the ground.
  • Poison sumac ( Toxicodendron vernix ) has compound leaves with 7–15 leaflets. Poison sumac never has only three leaflets.
  • Kudzu (Pueraria lobata) is a nontoxic edible vine that scrambles extensively over lower vegetation or grows high into trees. Kudzu is an invasive species in the southern United States. Like poison ivy, it has three leaflets, but the leaflets are bigger than those of poison ivy and are pubescent underneath with hairy margins.
  • Blackberries and raspberries (Rubus spp.) can resemble poison ivy, with which they may share territory; however, blackberries and raspberries almost always have thorns on their stems, whereas poison ivy stems are smooth. Also, the three-leaflet pattern of some blackberry and raspberry leaves changes as the plant grows: Leaves produced later in the season have five leaflets rather than three. Blackberries and raspberries have many fine teeth along the leaf edge, the top surface of their leaves is very wrinkled where the veins are, and the bottom of the leaves is light minty-greenish white. Poison ivy is all green. The stem of poison ivy is brown and cylindrical, while blackberry and raspberry stems can be green, can be squared in cross-section, and can have prickles. Raspberries and blackberries are never truly vines; they do not attach to trees to support their stems.
  • Strawberries ( Fragaria ), wild or cultivated, have trifoliate leaves and a red vine, and can be found in similar ecosystems. However, strawberry leaflets are serrated and have same-length petiolules. The stems also have small trichomes, which poison ivy lacks.
  • The thick vines of riverbank grape (Vitis riparia), with no rootlets visible, differ from the vines of poison ivy, which have so many rootlets that the stem going up a tree looks furry. Riverbank grapevines are purplish in color, tend to hang away from their support trees, and have shreddy bark; poison ivy vines are brown, attached to their support trees, and do not have shreddy bark.
  • Fragrant sumac ( Rhus aromatica ) has a very similar appearance to poison ivy. While both species have three leaflets, the center leaflet of poison ivy is on a long stalk, while the center leaflet of fragrant sumac does not have an obvious stalk. When crushed, fragrant sumac leaves have a fragrance similar to citrus, while poison ivy has little or no distinct fragrance. Fragrant sumac produces flowers before the leaves in spring, while poison ivy produces flowers after the leaves emerge. Flowers and fruits of fragrant sumac are at the end of the stem but occur along the middle of the stem of poison ivy. Fragrant sumac fruit ripens to a deep reddish color and is covered with tiny hairs, while poison ivy fruit is smooth and ripens to a whitish color.
  • Hoptree ( Ptelea trifoliata ) has leaves that are remarkably similar. It is, however, a much larger plant, so confusion is unlikely for any but the smallest specimens. The flowers and seeds are also easily distinguished from those of poison ivy.

Similar allergenic plants

Taxonomy

Subspecies [14] [15] [16]

Caquistle or caxuistle is the Nahuatl term for the species.

Distribution and habitat

T. radicans grows throughout much of North America, including the Canadian Maritime provinces, Quebec, Ontario, and all US states east of the Rocky Mountains, [17] as well as in the mountainous areas of Mexico [7] up to around 1,500 m (4,900 ft). [1] It is normally found in wooded areas, especially along edge areas where the tree line breaks and allows sunshine to filter through. It also grows in exposed rocky areas, open fields, and disturbed areas.

It may grow as a forest understory plant, although it is only somewhat shade-tolerant. [7] The plant is extremely common in suburban and exurban areas of New England, the Mid-Atlantic, and the Southeastern United States. The similar species T. diversilobum (western poison oak) and T. rydbergii (western poison ivy) are found in western North America, and T. orientale in Taiwan, Japan, Korea and Sakhalin.

T. radicans rarely grows at altitudes above 1,500 m (4,900 ft), although the altitude limit varies in different locations. [7] The plants can grow as a shrub up to about 1.2 m (4 ft) tall, as a groundcover 10–25 cm (4–10 in) high, or as a climbing vine on various supports. Older vines on substantial supports send out lateral branches that may be mistaken for tree limbs at first glance.

It grows in a wide variety of soil types, and soil pH from 6.0 (acidic) to 7.9 (moderately alkaline). It is not particularly sensitive to soil moisture, although it does not grow in desert or arid conditions. It can grow in areas subject to seasonal flooding or brackish water. [7]

It is more common now than when Europeans first arrived in North America. The development of real estate adjacent to wild, undeveloped land has engendered "edge effects", enabling poison ivy to form vast, lush colonies in these areas. It is listed as a noxious weed in the US states of Minnesota and Michigan and in the Canadian province of Ontario.

Outside North America, T. radicans is also found in parts of China. [16]

Poison ivy is particularly sensitive to carbon dioxide levels, greatly benefiting from higher concentrations in the atmosphere. Higher carbon dioxide levels increase the rate of plant growth, and cause them to produce more unsaturated urushiol, which causes stronger reactions in humans. [18] Poison ivy's growth and potency has already doubled since the 1960s, and it could double again once carbon dioxide levels reach 560 ppm. [19]

Ecology

The fruits are a favorite winter food of some birds and other animals, including wild turkeys. [20] Seeds are spread mainly by animals and remain viable after passing through the digestive tract. Birds may spread the seeds by regurgitation. [21]

Toxicity

A video describing the effects of poison ivy on the body
Blisters from contact with poison ivy Urushiol induced contact dermatitis.jpg
Blisters from contact with poison ivy

Urushiol-induced contact dermatitis is the allergic reaction caused by poison ivy. In extreme cases, a reaction can progress to anaphylaxis. Around 15 to 25 percent of people have no allergic reaction to urushiol, but most people have a greater reaction with repeated or more concentrated exposure. [22] [23] Typically, the rash from the urushiol oil lasts about five to twelve days, but in extreme cases, it can last a month or more. [24]

Over 350,000 people are affected by urushiol annually in the United States. [25]

The pentadecyl catechols of the oleoresin within the sap of poison ivy and related plants causes the allergic reaction; the plants produce a mixture of pentadecylcatechols, which collectively is called urushiol. After injury, the sap leaks to the surface of the plant where the urushiol becomes a blackish lacquer after contact with oxygen. [4] [26]

Urushiol binds to the skin on contact, where it causes severe itching that develops into reddish inflammation or uncoloured bumps, and then blistering. These lesions may be treated with Calamine lotion, Burow's solution compresses, dedicated commercial poison ivy itch creams, or baths to relieve discomfort, [27] though recent studies have shown some traditional medicines to be ineffective. [28] [29] Over-the-counter products to ease itching—or simply oatmeal baths and baking soda—are now recommended by dermatologists for the treatment of poison ivy. [30]

A plant-based remedy cited to counter urushiol-induced contact dermatitis is jewelweed, though jewelweed extracts had no positive effect in clinical studies. [31] [32] [33] [34] Others argue that prevention of lesions is easy if one practices effective washing, using plain soap, scrubbing with a washcloth, and rinsing three times within 2–8 hours of exposure. [35]

The oozing fluids released by scratching blisters do not spread the poison. The fluid in the blisters is produced by the body and it is not urushiol itself. [36] The appearance of a spreading rash indicates that some areas received more of the poison and reacted sooner than other areas or that contamination is still occurring from contact with objects to which the original poison was spread. Those affected can unknowingly spread the urushiol inside the house, on phones, doorknobs, couches, counters, desks, and so on, thus in fact repeatedly coming into contact with poison ivy and extending the length of time of the rash. If this has happened, wipe down the surfaces with bleach or a commercial urushiol removal agent. The blisters and oozing result from blood vessels that develop gaps and leak fluid through the skin; if the skin is cooled, the vessels constrict and leak less. [37] If plant material with urushiol is burned and the smoke then inhaled, this rash will appear on the lining of the lungs, causing extreme pain and possibly fatal respiratory difficulty. [36] If poison ivy is eaten, the mucus lining of the mouth and digestive tract can be damaged. [38] An urushiol rash usually develops within a week of exposure and can last 1–4 weeks, depending on severity and treatment. In rare cases, urushiol reactions may require hospitalization. [36]

Urushiol oil can remain active for several years, so handling dead leaves or vines can cause a reaction. In addition, oil transferred from the plant to other objects (such as pet fur) can cause the rash if it comes into contact with the skin. [39] [36] Clothing, tools, and other objects that have been exposed to oil should be washed to prevent further reactions. [40]

People who are sensitive to urushiol can also experience a similar rash from mangoes. Mangoes are in the same family (Anacardiaceae) as poison ivy; the sap of the mango tree and skin of mangoes has a chemical compound similar to urushiol. [41] A related allergenic compound is present in the raw shells of cashews. [42] Similar reactions have been reported occasionally from contact with the related Fragrant Sumac ( Rhus aromatica ) and Japanese lacquer tree.[ citation needed ] These other plants are also in the family Anacardiaceae.

Treatment

Immediate washing with soap and cold water or rubbing alcohol may help prevent a reaction. [43] During a reaction, Calamine lotion or diphenhydramine may help mitigate symptoms. Corticosteroids, either applied to the skin or taken by mouth, may be appropriate in extreme cases. An astringent containing aluminum acetate (such as Burow's solution) may also provide relief and soothe the uncomfortable symptoms of the rash. [44]

Related Research Articles

<span class="mw-page-title-main">Anacardiaceae</span> Family of flowering plants that includes cashew and mango

The Anacardiaceae, commonly known as the cashew family or sumac family, are a family of flowering plants, including about 83 genera with about 860 known species. Members of the Anacardiaceae bear fruits that are drupes and in some cases produce urushiol, an irritant. The Anacardiaceae include numerous genera, several of which are economically important, notably cashew, mango, Chinese lacquer tree, yellow mombin, Peruvian pepper, poison ivy, poison oak, sumac, smoke tree, marula and cuachalalate. The genus Pistacia is now included, but was previously placed in its own family, the Pistaciaceae.

<i>Toxicodendron</i> Genus of plants

Toxicodendron is a genus of flowering plants in the sumac family, Anacardiaceae. It contains trees, shrubs and woody vines, including poison ivy, poison oak, and the lacquer tree. All members of the genus produce the skin-irritating oil urushiol, which can cause a severe allergic reaction. The generic name is derived from the Greek words τοξικός (toxikos), meaning "poison," and δένδρον (dendron), meaning "tree". The best known members of the genus in North America are poison ivy (T. radicans), practically ubiquitous throughout most of eastern North America, and western poison oak, similarly ubiquitous throughout much of the western part of the continent.

<span class="mw-page-title-main">Sumac</span> Related species of plants in the family Anacardiaceae

Sumac or sumach is any of about 35 species of flowering plants in the genus Rhus and related genera in the cashew family (Anacardiaceae). Sumacs grow in subtropical and temperate regions throughout every continent except Antarctica and South America. Sumac is used as a spice, as a dye, and in medicine.

<span class="mw-page-title-main">Urushiol</span> Oily mixture of organic compounds

Urushiol is an oily mixture of organic compounds with allergenic properties found in plants of the family Anacardiaceae, especially Toxicodendronspp., Comocladia spp. (maidenplums), Metopium spp. (poisonwood), and also in parts of the mango tree as well as the fruit of the cashew tree.

<i>Impatiens</i> Genus of flowering plants

Impatiens is a genus of more than 1,000 species of flowering plants, widely distributed throughout the Northern Hemisphere and the tropics. Together with the genus Hydrocera, Impatiens make up the family Balsaminaceae.

<span class="mw-page-title-main">Contact dermatitis</span> Human disease

Contact dermatitis is a type of acute or chronic inflammation of the skin caused by exposure to chemical or physical agents. Symptoms of contact dermatitis can include itchy or dry skin, a red rash, bumps, blisters, or swelling. These rashes are not contagious or life-threatening, but can be very uncomfortable.

<i>Toxicodendron diversilobum</i> Species of plant

Toxicodendron diversilobum, commonly named Pacific poison oak or western poison oak, is a woody vine or shrub in the sumac family, Anacardiaceae. It is widely distributed in western North America, inhabiting conifer and mixed broadleaf forests, woodlands, grasslands, and chaparral biomes. Peak flowering occurs in May. Like other members of the genus Toxicodendron, T. diversilobum causes itching and allergic rashes in most people after contact by touch or smoke inhalation. Despite its name, it is not closely related to oaks, nor is it a true tree.

<i>Parthenocissus quinquefolia</i> Species of flowering plant

Parthenocissus quinquefolia, known as Virginia creeper, Victoria creeper, five-leaved ivy, or five-finger, is a species of flowering vine in the grape family, Vitaceae. It is native to eastern and central North America, from southeastern Canada and the eastern United States west to Manitoba and Utah, and south to eastern Mexico and Guatemala.

<i>Toxicodendron vernix</i> Species of plant

Toxicodendron vernix, commonly known as poison sumac, or swamp-sumach, is a woody shrub or small tree growing to 9 metres (30 feet) tall. It was previously known as Rhus vernix. This plant is also known as thunderwood, particularly where it occurs in the southern United States. All parts of the plant contain a resin called urushiol that causes skin and mucous membrane irritation to humans. Urushiol is the same chemical that poison ivy is covered in. When the plant is burned, inhalation of the smoke may cause the rash to appear on the lining of the lungs, causing extreme pain and possibly fatal respiratory difficulty.

<span class="mw-page-title-main">Urushiol-induced contact dermatitis</span> Medical condition

Urushiol-induced contact dermatitis is a type of allergic contact dermatitis caused by the oil urushiol found in various plants, most notably sumac family species of the genus Toxicodendron: poison ivy, poison oak, poison sumac, and the Chinese lacquer tree. The name is derived from the Japanese word for the sap of the Chinese lacquer tree, urushi. Other plants in the sumac family also contain urushiol, as do unrelated plants such as Ginkgo biloba.

<span class="mw-page-title-main">Allergic contact dermatitis</span> Medical condition

Allergic contact dermatitis (ACD) is a form of contact dermatitis that is the manifestation of an allergic response caused by contact with a substance; the other type being irritant contact dermatitis (ICD).

<i>Toxicodendron rydbergii</i> Species of plant

Toxicodendron rydbergii, the western poison ivy or northern poison oak, is a species of Toxicodendron in the cashew family native to North America.

<i>Toxicodendron pubescens</i> Eastern poison oak

Toxicodendron pubescens, commonly known as Atlantic poison oak, is an upright shrub that can grow to 1 metre (3 feet) tall. Its leaves are 15 centimetres (6 inches) long, alternate, with three leaflets on each. The leaflets are usually hairy and are variable in size and shape, but most often resemble white oak leaves; they usually turn yellow or orange in autumn. The fruit is small, round, and yellowish or greenish. It is not closely related to true oaks.

<i>Impatiens capensis</i> Species of flowering plant

Impatiens capensis, the orange jewelweed, common jewelweed, spotted jewelweed, jewelweed, spotted touch-me-not, or orange balsam, is an annual plant in the family Balsaminaceae that is native to North America. It is common in bottomland soils, ditches, and along creeks, often growing side by side with its less common relative, yellow jewelweed.

<i>Toxicodendron vernicifluum</i> Species of plant

Toxicodendron vernicifluum, also known by the common name Chinese lacquer tree, is an Asian tree species of genus Toxicodendron native to China and the Indian subcontinent, and cultivated in regions of China, Japan and Korea. Other common names include Japanese lacquer tree, Japanese sumac, and varnish tree. The trees are cultivated and tapped for their toxic sap, which is used as a highly durable lacquer to make Chinese, Japanese, and Korean lacquerware.

<span class="mw-page-title-main">Tecnu</span>

Tecnu is an over-the-counter skin cleanser manufactured by Tec Laboratories, a pharmaceutical company based in Albany, Oregon. It is intended for use by humans and furry pets after topical exposure to urushiol, the active ingredient in poison oak, poison ivy, and poison sumac. Tecnu is made from deodorized mineral spirits, water, propylene glycol, octylphenoxy-polythoxethanol, mixed fatty acid soap, and fragrance.

<i>Lithraea caustica</i> Species of plant

Lithraea caustica is a species of flowering plants in the soapberry family Anacardiaceae. This plant is endemic to central Chile; an example occurrence is in the area of La Campana National Park and Cerro La Campana. The tree is a well known human allergen and can cause a rash of the skin, the effects of and susceptibility to which can vary greatly among individuals.

<i>Rhus aromatica</i> Species of shrub

Rhus aromatica, the fragrant sumac, is a deciduous shrub in the family Anacardiaceae native to North America. It is found in southern Canada and nearly all of the lower 48 states except peninsular Florida.

<span class="mw-page-title-main">Poison ivy</span> Allergenic plant of Asia and North America

Poison ivy is a type of allergenic plant in the genus Toxicodendron native to Asia and North America. Formerly considered a single species, Toxicodendron radicans, poison ivies are now generally treated as a complex of three separate species: Toxicodendron radicans, Toxicodendron rydbergii, and Toxicodendron orientale. They are well known for causing urushiol-induced contact dermatitis, an itchy, irritating, and sometimes painful rash, in most people who touch them. The rash is caused by urushiol, a clear liquid compound in the plant's sap. They are variable in appearance and habit, and despite its common name, it is not a "true" ivy (Hedera), but rather a member of the cashew and pistachio family (Anacardiaceae). T. radicans is commonly eaten by many animals, and the seeds are consumed by birds, but poison ivy is most often thought of as an unwelcome weed.

<i>Toxicodendron orientale</i> Species of flowering plant

Toxicodendron orientale is an allergenic East Asian flowering plant in the genus Toxicodendron. The species was first characterized and named by Edward Lee Greene in 1905. T. orientale is known to grow in Sakhalin, Japan, Taiwan, South central China, and South Korea. It was introduced to parts of Uzbekistan.

References

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  15. ↑ Toxicodendron radicans (L.) Kuntze. Plants of the World Online. cience.kew.org
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  18. ↑ Mohan, Jacqueline E.; Ziska, Lewis H.; Schlesinger, William H.; Thomas, Richard B.; Sicher, Richard C.; George, Kate; Clark, James S. (2006). "Biomass and toxicity responses of poison ivy (Toxicodendron radicans) to elevated atmospheric CO2". Proceedings of the National Academy of Sciences. 103 (24): 9086–9089. Bibcode:2006PNAS..103.9086M. doi: 10.1073/pnas.0602392103 . PMC   1474014 . PMID   16754866.
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  24. ↑ "Poison Ivy, Poison Oak and Poison Sumac FAQs".
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  32. ↑ Gibson, MR; Maher, FT (1950). "Activity of jewelweed and its enzymes in the treatment of Rhus dermatitis". Journal of the American Pharmaceutical Association. 39 (5): 294–6. doi:10.1002/jps.3030390516. PMID   15421925.
  33. ↑ Guin, J. D.; Reynolds, R. (1980). "Jewelweed treatment of poison ivy dermatitis". Contact Dermatitis. 6 (4): 287–8. doi:10.1111/j.1600-0536.1980.tb04935.x. PMID   6447037. S2CID   46551170.
  34. ↑ Zink, B. J.; Otten, E. J.; Rosenthal, M.; Singal, B. (1991). "The effect of jewel weed in preventing poison ivy dermatitis". Journal of Wilderness Medicine. 2 (3): 178–182. doi:10.1580/0953-9859-2.3.178. S2CID   57162394.
  35. ↑ Archived at Ghostarchive and the Wayback Machine : Extreme Deer Habitat (2014-06-22). "How to never have a serious poison ivy rash again". YouTube . Retrieved 2016-07-26.
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  37. ↑ Editors of Prevention (2010). The Doctors Book of Home Remedies: Quick Fixes, Clever Techniques, and Uncommon Cures to Get You Feeling Better Fast. Rodale. pp. 488–. ISBN   978-1-60529-866-5.
  38. ↑ Lewis, Robert Alan (1998). Lewis' dictionary of toxicology. CRC Press. pp. 901–. ISBN   978-1-56670-223-2.
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  42. ↑ Rosen, T.; Fordice, D. B. (April 1994). "Cashew Nut Dermatitis". Southern Medical Journal. 87 (4): 543–546. doi:10.1097/00007611-199404000-00026. PMID   8153790.
  43. ↑ "Misconceptions About Treating Poison Ivy and Oak Rash". teclabsinc.com. Archived from the original on 2014-08-26.
  44. ↑ Gladman, Aaron C. (June 2006). "Toxicodendron Dermatitis: Poison Ivy, Oak, and Sumac". Wilderness & Environmental Medicine. 17 (2): 120–128. doi: 10.1580/PR31-05.1 . PMID   16805148.
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