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31-404: T. orientale Greene T. radicans (L.) Kuntze T. rydbergii ( Small ex Rydb. ) Greene 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 (photo on

62-443: A blister, as can any friction on the skin if continued long enough. This kind of blister is most common after walking long distances or by wearing old or poorly fitting shoes. Blisters are most common on the hands and feet, as these extremities are susceptible while walking, running, or performing repetitive motions, such as joystick manipulation whilst playing certain video games, certain sports (e.g., baseball pitching), digging with

93-400: A chemical compound similar to urushiol. A related allergenic compound is present in the raw shells of cashews . Similar reactions have been reported occasionally from contact with the related fragrant sumac ( Rhus aromatica ) and Japanese lacquer tree . These other plants are also in the family Anacardiaceae. Toxicodendron orientale Toxicodendron orientale ( Asian poison ivy )

124-503: 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 . Three species of poison ivy are generally recognised; they are sometimes considered subspecies of Toxicodendron radicans : Poison ivies can grow as small plants, shrubs, or climbing vines. They are commonly characterized by clusters of leaves, each containing three leaflets, hence

155-401: A month or more. A 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. 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

186-468: 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. Over 350,000 people are affected by urushiol annually in the United States. The oozing fluids released by scratching blisters do not spread the poison. The fluid in the blisters is produced by the body and it

217-399: A shovel, playing guitar or bass, etc. Blisters form more easily on damp skin than on dry or soaked skin, and are more common in warm conditions. Less-aggressive rubbing over long periods of time may cause calluses to form rather than a blister. Both blisters and calluses can lead to more serious complications, such as foot ulceration and infection, particularly when sensation or circulation

248-487: A variety of ways. Blisters on the feet can be prevented by wearing comfortable, well-fitting shoes and clean socks. Inherently ill-fitting or stiffer shoes, such as high heels and dress shoes, present a larger risk of blistering. Blisters are more likely to develop on skin that is moist, so socks that manage moisture or frequent sock changes will aid those with particularly sweaty feet. While exercising or playing sports, special sports socks can help keep feet drier and reduce

279-554: Is mustard gas . A blood blister usually forms when a minute blood vessel close to the surface of the skin ruptures (breaks), and blood leaks into a tear between the layers of skin. This can happen if the skin is crushed, pinched or aggressively squeezed. There are also a number of medical conditions that cause blisters. The most common are chickenpox , herpes , impetigo , and a form of eczema called dyshidrosis . Other, much rarer conditions that cause blisters include: Friction blisters are caused by excess shear stress between

310-634: 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 . Toxicodendron orientale is a climbing vine that grows on trees or other supports. The deciduous leaves of T. orientale are trifoliate and grow to be 3-10 cm in length. Young branches are covered with small brown hairs that turn into red lenticels as

341-465: Is impaired, as in the case of diabetes , neuropathy or peripheral artery disease (PAD). This type of blistering is one of the tools used to determine the degree of burns sustained. First and second degree burns may result in blistered skin; however, it is characteristic of second degree burns to blister immediately, whereas first degree burns can have blisters after a couple of days. Sunburn can also result in blisters. Blisters can also form on

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372-461: Is not urushiol itself. 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, door knobs, couches, counters, desks, and so on, thus in fact repeatedly coming into contact with poison ivy and extending

403-541: The Middle Dutch bluyster and was a modification of the Old French blostre , which meant a leprous nodule—a rise in the skin due to leprosy . In dermatology today, the words vesicle and bulla refer to blisters of smaller or greater size, respectively. To heal properly, a blister should not be popped unless medically necessary. If popped, bacteria can enter. The excess skin should not be removed because

434-426: 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. Typically, the rash from the urushiol oil lasts about five to twelve days, but in extreme cases it can last

465-399: The bottom and surface of the skin and the body. The strata of skin around the stratum spinosum are most susceptible to shear. As the stratum spinosum tears away from the connecting tissues below, plasma from the cells diffuses out. This plasma solution helps new cells divide and grow into new connective tissues and epidermal layers. The clear fluid will be reabsorbed as new cells develop and

496-452: The branches mature. T. orientale flowers from May to June. The small yellow-green flowers grow in groups from the leaf axils . The flowers mature into yellow-brown fruit in August to September. All parts of Toxicodendron orientale contain urushiol , which is known to cause severe contact dermatitis . Blister The word "blister" entered English in the 14th century. It came from

527-417: The chance of blisters. Before going for a long walk, it is also important to ensure that shoes or hiking boots have been properly broken in. Even before a "hot" or irritated area on the foot is felt, taping a protective layer of padding or a friction-reducing interface between the affected area and the footwear can prevent the formation of a blister. Bandages, moleskin and tapes generally must be applied to

558-458: The common expression "leaves of three, let it be". 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 produce white berries in the fall a few millimeters in diameter. Urushiol-induced contact dermatitis is the allergic reaction caused by poison ivy. In extreme cases,

589-538: The foot daily, and most have a very high coefficient of friction (COF), but a friction-management patch applied to the shoe will remain in place much longer, throughout many changes of socks and insoles. This type of intervention may be used with footwear that is worn daily, with specialty shoes and boots like hockey skates, ice skates, inline skates, ski boots and cleats, or even with orthotic braces and splints. For periods of sustained use such as hiking and trail running, especially where water ingress or moisture build up in

620-401: The friction developed by the rubbing against the bars. To further reduce the occurrence one can tape the hands, and there are also a number of products on the market that claim to reduce the occurrence of blisters. These are all intended to be worn as a liner underneath a glove. The majority of these offerings simply add padding, and create a layer that reduces the coefficient of friction between

651-567: The hands and feet as a result of tissue damage incurred by frostbite . Sometimes, the skin will blister when it comes into contact with a cosmetic, detergent, solvent, or other chemical such as nickel sulfate , Balsam of Peru , or urushiol ( poison ivy , poison oak , poison sumac ). This is known as contact dermatitis . Blisters can also develop as a result of an allergic reaction to an insect bite or sting. Some chemical warfare agents, known as blister agents or vesicants, cause large, painful blisters wherever they contact skin; an example

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682-399: 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 is cooled, the vessels constrict and leak less. If plant material with urushiol is burned and the smoke then inhaled, this rash will appear on the lining of

713-399: The lungs, causing extreme pain and possibly fatal respiratory difficulty. If poison ivy is eaten, the mucus lining of the mouth and digestive tract can be damaged. 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

744-425: 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 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

775-473: The shoe or boot can occur, moisture wicking liner socks can provide the required friction protection. To avoid friction blisters on the hands, gloves should be worn when using tools such as a shovel or pickaxe, doing manual work such as gardening, or using sports equipment like golf clubs or baseball bats. Oars used for competitive rowing are known for causing frequent blisters on the hands of oarsmen. Weightlifters are also prone to blisters as are gymnasts from

806-426: The skin and the glove. A lubricant , typically talcum powder , can be used to reduce friction between skin and apparel in the short term. People put talcum powder inside gloves or shoes for this purpose, although this type of lubricant can actually increase the friction in the long term as it absorbs moisture. Increased friction makes blisters more likely. Sunscreen and protective clothing should also be used during

837-404: The skin underneath needs the top layer to heal properly. A blister may form when the skin has been damaged by friction or rubbing, heat, cold or chemical exposure. Fluid collects between the upper layers of skin (the epidermis ) and the layers below (the dermis ). This fluid cushions the tissue underneath, protecting it from further damage and allowing it to heal. Intense rubbing can cause

868-508: The skin. Clothing, tools, and other objects that have been exposed to oil should be washed to prevent further reactions. Immediate washing with soap and cold water or rubbing alcohol may help prevent a reaction. 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

899-411: The swollen appearance will subside. Painful blisters located on hands ( palmar surface ) and feet ( plantar surface ) are due to tissue shearing deeper in the epidermis, near nerve endings. Lower tissues are more susceptible to infection. Friction blisters, caused by rubbing against the skin, can be prevented by reducing the friction to a level where blisters will not form. This can be accomplished in

930-406: The treatment of poison ivy. A plant-based remedy cited to counter urushiol-induced contact dermatitis is jewelweed , though jewelweed extracts had no positive effect in clinical studies. 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. The pentadecyl catechols of

961-566: The uncomfortable symptoms of the rash. 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, though recent studies have shown some traditional medicines to be ineffective. Over-the-counter products to ease itching—or simply oatmeal baths and baking soda —are now recommended by dermatologists for

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