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Urushiol-induced Contact Dermatitis
Urushiol-induced contact dermatitis (also called Toxicodendron dermatitis or Rhus 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, Toxicodendron diversilobum, poison oak, poison sumac, and the Toxicodendron vernicifluum, Chinese lacquer tree. The name is derived from the Japanese word for the sap of the Chinese lacquer tree, ''urushi''. Other plants in the Anacardiaceae, sumac family (including mango, pistachio, the Burmese lacquer tree, the India marking nut tree, and the cashew) also contain urushiol, as do unrelated plants such as ''Ginkgo biloba.'' As is the case with all contact dermatitis, urushiol-induced allergy, allergic rashes are a Type IV hypersensitivity, Type IV hypersensitivity reaction, also known as delayed-type hypersensitivity. Symptoms include itching, inflammation, oozing, and, in severe cases, a burning sensation. The American ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Itching
An itch (also known as pruritus) is a sensation that causes a strong desire or reflex to scratch. Itches have resisted many attempts to be classified as any one type of sensory experience. Itches have many similarities to pain, and while both are unpleasant sensory experiences, their behavioral response patterns are different. Pain creates a withdrawal reflex, whereas itches leads to a scratch reflex. Unmyelinated nerve fibers for itches and pain both originate in the skin. Information for them is conveyed centrally in two distinct systems that both use the same nerve bundle and spinothalamic tract. Classification Most commonly, an itch is felt in one place. If it is felt all over the body, then it is called ''generalized itch'' or ''generalized pruritus''. Generalized itch is infrequently a symptom of a serious underlying condition, such as cholestatic liver disease. If the sensation of itching persists for six weeks or longer, then it is called ''chronic itch'' or ''ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ginkgo Biloba
''Ginkgo biloba'', commonly known as ginkgo or gingko ( ), also known as the maidenhair tree, is a species of gymnosperm tree native to East Asia. It is the last living species in the order Ginkgoales, which first appeared over 290 million years ago. Fossil, Fossils very similar to the living species, belonging to the genus ''Ginkgo'', extend back to the Middle Jurassic epoch approximately 170 million years ago. The tree was cultivated early in human history, remains commonly planted, and is widely regarded as a living fossil. ''G. biloba'' is a long-lived, Disease resistance, disease-resistant, Dioecy, dioecious tree with unique fan-shaped Leaf, leaves, capable of Cloning, clonal reproduction, and known for its striking yellow autumn foliage and resilience in disturbed environments. It was known historically as “silver fruit” or “white fruit” in Chinese language, Chinese and called “ginkgo” due to a centuries-old transcription error. It is closely related to Cycad, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vesicle (dermatology)
A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this system is as a barrier against the external environment. Conditions of the human integumentary system constitute a broad spectrum of diseases, also known as dermatoses, as well as many nonpathologic states (like, in certain circumstances, melanonychia and racquet nails). While only a small number of skin diseases account for most visits to the physician, thousands of skin conditions have been described. Classification of these conditions often presents many nosological challenges, since underlying causes and pathogenetics are often not known. Therefore, most current textbooks present a classification based on location (for example, conditions of the mucous membrane), morphology ( chronic blistering conditions), cause ( skin conditions res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Papule
A papule is a small, well-defined bump in the skin lesion, skin. It may have a rounded, pointed or flat top, and may have a umbilication, dip. It can appear with a Peduncle (anatomy), stalk, be thread-like or look warty. It can be soft or firm and its surface may be rough or smooth. Some have Crust (dermatology), crusts or Scale (dermatology), scales. A papule can be flesh colored, yellow, white, brown, red, blue or purplish. There may be just one or many, and they may occur irregularly in different parts of the body or appear in clusters. It does not contain fluid but may progress to a pustule or vesicle (dermatology), vesicle. A papule is smaller than a Nodule (medicine), nodule; it can be as tiny as a pinhead and is typically less than 1 cm in width, according to some sources, and 0.5 cm according to others. When merged together, it appears as a plaque. A papule's colour might indicate its cause, such as white in Milium (dermatology), milia, red in eczema, yellowish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eczema
Dermatitis is a term used for different types of skin inflammation, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can vary from small to covering the entire body. Dermatitis is also called eczema but the same term is often used for the most common type of skin inflammation, atopic dermatitis. The exact cause of the condition is often unclear. Cases may involve a combination of allergy and poor venous return. The type of dermatitis is generally determined by the person's history and the location of the rash. For example, irritant dermatitis often occurs on the hands of those who frequently get them wet. Allergic contact dermatitis occurs upon exposure to an allergen, causing a hypersensitivity reaction in the skin. Prevention of atopic dermatitis is typically with essential fatty acids, and may be treated with moisturi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eastern United States
The Eastern United States, often abbreviated as simply the East, is a macroregion of the United States located to the east of the Mississippi River. It includes 17–26 states and Washington, D.C., the national capital. As of 2011, the Eastern United States had an estimated population exceeding 179 million, representing the majority (over 58 percent) of the total U.S. population. The three most populous cities in the Eastern United States are New York City, Chicago, and Philadelphia. Northeastern United States According to the United States Census Bureau, U.S. Census Bureau, the Northeastern United States comprises nine states, including (north to south): Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New Jersey, New York (state), New York, and Pennsylvania. The present-day Northeast is significantly smaller than the Northeastern Woodlands cultural area. The pre-Columbian Northeast had three major areas: the Coastal area, Saint Lawrence Lowlands, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern United States
The Southern United States (sometimes Dixie, also referred to as the Southern States, the American South, the Southland, Dixieland, or simply the South) is List of regions of the United States, census regions defined by the United States Census Bureau. It is between the Atlantic Ocean and the Western United States, with the Midwestern United States, Midwestern and Northeastern United States to its north and the Gulf of Mexico and Mexico to its south. Historically, the South was defined as all states south of the 18th-century Mason–Dixon line, the Ohio River, and the Parallel 36°30′ north, 36°30′ parallel.The South . ''Britannica''. Retrieved June 5, 2021. Within the South are different subregions such as the Southeastern United States, Southeast, South Central United States, South Central, Upland South, Upper South, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western United States
The Western United States (also called the American West, the Western States, the Far West, the Western territories, and the West) is List of regions of the United States, census regions United States Census Bureau. As American settlement in the U.S. Manifest destiny, expanded westward, the meaning of the term ''the West'' changed. Before around 1800, the crest of the Appalachian Mountains was seen as the American frontier, western frontier. The frontier moved westward and eventually the lands west of the Mississippi River were considered ''the West''. The U.S. Census Bureau's definition of the 13 westernmost states includes the Rocky Mountains and the Great Basin to the West Coast of the United States, Pacific Coast, and the mid-Pacific islands state, Hawaii. To the east of the Western United States is the Midwestern United States and the Southern United States, with Canada to the north and Mexico to the south. The West contains several major biomes, including arid and Sem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Forest Service
The United States Forest Service (USFS) is an agency within the United States Department of Agriculture, U.S. Department of Agriculture. It administers the nation's 154 United States National Forest, national forests and 20 United States National Grassland, national grasslands covering of land. The major divisions of the agency are the Chief's Office, National Forest System, State and Private Forestry, Business Operations, as well as Research and Development. The agency manages about 25% of federal lands and is the sole major national land management agency not part of the United States Department of the Interior, U.S. Department of the Interior (which manages the National Park Service, the U.S. Fish and Wildlife Service and the Bureau of Land Management). History In 1876, Congress formed the office of Special Agent in the Department of Agriculture to assess the quality and conditions of forests in the United States. Franklin B. Hough was appointed the head of the office. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States asserts sovereignty over five Territories of the United States, major island territories and United States Minor Outlying Islands, various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's List of countries and dependencies by area, third-largest land area and List of countries and dependencies by population, third-largest population, exceeding 340 million. Its three Metropolitan statistical areas by population, largest metropolitan areas are New York metropolitan area, New York, Greater Los Angeles, Los Angel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Academy Of Dermatology
The American Academy of Dermatology (AAD) is a non-profit professional organization of dermatologists in the United States and Canada, based in Rosemont, Illinois, near Chicago. It was founded in 1938 and has more than ''21,000'' members. The Academy grants fellowships and associate memberships, as well as fellowships for nonresidents of the United States or Canada. Since 1979, the AAD also publishes a monthly medical journal, the ''Journal of the American Academy of Dermatology''. To become a Fellow of the American Academy of Dermatology (FAAD), a physician must be a resident of the United States of America or Canada and certified by the American Board of Dermatology or in dermatology by the Royal College of Physicians and Surgeons of Canada. To become an associate member, a physician must have three years of experience in practice or as a teacher or graduate student of dermatology and must have had training that qualifies for examination by the American Board of Dermatology or t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type IV Hypersensitivity
Type IV hypersensitivity, in the Gell and Coombs classification of allergic reactions, often called delayed-type hypersensitivity, is a type of hypersensitivity reaction that can take a day or more to develop. Unlike the other types, it is not humoral (not antibody-mediated) but rather is a type of cell-mediated response. This response involves the interaction of T cells, monocytes, and macrophages. This reaction is caused when CD4+ Th1 cells recognize foreign antigen in a complex with the MHC class II on the surface of antigen-presenting cells. These can be macrophages that secrete IL-12, which stimulates the proliferation of further CD4+ Th1 cells. CD4+ T cells secrete IL-2 and interferon gamma (IFNγ), inducing the further release of other Th1 cytokines, thus mediating the immune response. Activated CD8+ T cells destroy target cells on contact, whereas activated macrophages produce hydrolytic enzymes and, on presentation with certain intracell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
