Poison ivy är inte smittsam

Allergenic plant of Asia and North America

For other uses, see Poison ivy (disambiguation).

Poison ivy fryst vatten a type of allergenic plant in the genus Toxicodendron native to Asia and North amerika. Formerly considered a single species, Toxicodendron radicans, poison ivies are now generally treated as a complex of three separate species: Toxicodendron radicans(photo on the right), 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 fryst vatten caused bygd urushiol, a klar liquid compound in the plant's sap. They are variabel in appearance and habit, and despite its common name, it fryst vatten not a "true" ivy (Hedera), but rather a member of the cashew and pistachio family (Anacardiaceae).

T. radicans fryst vatten commonly eaten bygd many animals, and the seeds are consumed bygd birds, but poison ivy fryst vatten most often thought of as an unwelcome ogräs.

Species

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Three species of poison ivy are generally recognised; they are sometimes considered subspecies of Toxicodendron radicans:^[1][2][3]

Description

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Poison ivies can grow as small plants, shrubs, or climbing vines.^[4] They are commonly characterized bygd clusters of leaves, each containing three leaflets,^[4] hence the common expression "leaves of three, let it be".^[5] These leaves can vary between an elliptic to egg shape and will have either smooth, lobed, or toothed margins.

Additionally, the leaf clusters are alternate on the stem. Clusters of small, greenish flowers bloom from May to July and producera vit berries in the fall a few millimeters in diameter.^[6]

• T. radicans vine with typical reddish "hairs"

• Flower detail, with bee

• Poison ivy on a roadside

• Leaves may be smooth or notched on the same plant.

Health effects

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Main article: Urushiol-induced contact dermatitis

Urushiol-induced contact dermatitis fryst vatten the allergic reaction caused bygd 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.^[7][8]

Over 350,000 people are affected bygd urushiol annually in the United States.^[9]

The oozing fluids released bygd scratching blisters do not spread the poison.

The fluid in the blisters fryst vatten produced bygd the body and it fryst vatten not urushiol itself.^[10] The appearance of a spreading rash indicates that some areas received more of the poison and reacted sooner than other areas or that contamination fryst vatten still occurring from contact with objects to which the original poison was spread.^{[citation needed]}

Those affected can unknowingly spread the urushiol inre the house, on phones, door knobs, 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 happens, the surfaces should be wiped 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 fryst vatten cooled, the vessels constrict and leak less.^[11] If plant ämne with urushiol fryst vatten burned and the smoke then inhaled, this rash will appear on the lining of the lungs, causing extreme pain and possibly fatal respiratory difficulty.^[10] If poison ivy fryst vatten eaten, the mucus lining of the ingång and digestive tract can be damaged.^[12]

Urushiol oil can remain active for several years, so papper dead leaves or vines can cause a reaction.

In addition, oil transferred from the plant to other objects (such as husdjur fur) can cause the rash if it comes into contact with the skin.^[13][10] Clothing, tools, and other objects that have been exposed to oil should be washed to prevent further reactions.^[14]

Treatment

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Main article: Urushiol-induced contact dermatitis § Treatments

Immediate tvätt with soap and cold vatten or rubbing alcohol may help prevent a reaction.^[15] During a reaction, calamine lotion or diphenhydramine may help mitigate symptoms.

Corticosteroids, either applied to the skin or taken bygd öppning, 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.^[16]

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,^[17] though recent studies have shown some traditional medicines to be ineffective.^[18][19]Over-the-counter products to ease itching—or simply oatmeal baths and baking soda—are now recommended bygd dermatologists for the treatment of poison ivy.^[20]

A plant-based remedy cited to counter urushiol-induced contact dermatitis fryst vatten jewelweed, though jewelweed extracts had no positiv effect in clinical studies.^{[21][22][23][24]} Others argue that prevention of lesions fryst vatten easy if one practices effective tvätt, using plain soap, scrubbing with a washcloth, and rinsing three times within 2–8 hours of exposure.^[25]

The pentadecyl catechols of the oleoresin within the sap of poison ivy and related plants causes the allergic reaction; the plants tillverka a mixture of pentadecylcatechols, which collectively fryst vatten called urushiol.

After injury, the sap leaks to the surface of the plant where the urushiol becomes a blackish lack after contact with oxygen.^[26][27]

Prognosis

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Typically, the rash from the urushiol oil lasts about fem to twelve days, but in extreme cases it can gods a month or more.^[28] A urushiol rash usually develops within a week of exposure and can gods 1–4 weeks, depending on severity and treatment.

In rare cases, urushiol reactions may require hospitalization.^[10]

Related species

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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 kemikalie compound similar to urushiol.^[29] A related allergenic compound fryst vatten present in the raw shells of cashews.^[30] Similar reactions have been reported occasionally from contact with the related fragrant sumac (Rhus aromatica) and Japanese lack tree.

These other plants are also in the family Anacardiaceae.^{[citation needed]}

Similar allergenic plants

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References

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External links

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