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Actinic Cheilitis
Actinic cheilitis is cheilitis (lip inflammation) caused by long term sunlight exposure. Essentially it is a burn, and a variant of actinic keratosis which occurs on the lip. It is a premalignant condition, as it can develop into squamous cell carcinoma (a type of mouth cancer). Signs and symptoms AC almost always affects the lower lip and only rarely the upper lip, probably because the lower lip is more exposed to the sun. In the unusual cases reported where it affects the upper lip, this may be due to upper lip prominence. The commissures (corners of the mouth) are not usually involved. Affected individuals may experience symptoms such as a dry sensation and cracking of the lips. It is usually painless and persistent. The appearance is variable. White lesions indicate hyperkeratosis. Red, erosive or ulcerative lesions indicate atrophy, loss of epithelium and inflammation. Early, acute lesions may be erythematous (red) and edematous (swollen). With months and years of sun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheilitis
Cheilitis is a medical condition characterized by inflammation of the lips. The inflammation may include the perioral skin (the skin around the mouth), the vermilion border, or the labial mucosa. The skin and the vermilion border are more commonly involved, as the mucosa is less affected by inflammatory and allergic reactions. ''Cheilitis'' is a general term, and there are many recognized types and different causes. According to its onset and course, cheilitis can be either acute or chronic. Most cheilitis is caused by exogenous factors such as dryness (chapping) and acute sun exposure. Allergic tests may identify allergens that cause cheilitis. Chapped lips Chapped lips (also known as cheilitis simplex or common cheilitis) is characterized by the cracking, fissuring, and peeling of the skin of the lips, and is one of the most common types of cheilitis. While both lips may be affected, the lower lip is the most common site. There may also be burning or the formation of large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xeroderma Pigmentosum
Xeroderma pigmentosum (XP) is a genetic disorder in which there is a decreased ability to repair DNA damage such as that caused by ultraviolet (UV) light. Symptoms may include a severe sunburn after only a few minutes in the sun, freckling in sun-exposed areas, dry skin and changes in skin pigmentation. Nervous system problems, such as hearing loss, poor coordination, loss of intellectual function and seizures, may also occur. Complications include a high risk of skin cancer, with about half having skin cancer by age 10 without preventative efforts, and cataracts. There may be a higher risk of other cancers such as brain cancers. XP is autosomal recessive, with mutations in at least nine specific genes able to result in the condition. Normally, the damage to DNA which occurs in skin cells from exposure to UV light is repaired by nucleotide excision repair. In people with xeroderma pigmentosum, this damage is not repaired. As more abnormalities form in DNA, cells malfunction and e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tissue Biopsy
A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a disease. The tissue is then fixed, dehydrated, embedded, sectioned, stained and mounted before it is generally examined under a microscope by a pathologist; it may also be analyzed chemically. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. An incisional biopsy or core biopsy samples a portion of the abnormal tissue without attempting to remove the entire lesion or tumor. When a sample of tissue or fluid is removed with a needle in such a way that cells are removed without preserving the histological architecture of the tissue cells, the procedure is called a needle aspiration biopsy. Biopsies are most commonly performed for insight into possible cancerous or inflammatory conditions. History T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dentures
Dentures (also known as false teeth) are prosthetic devices constructed to replace missing teeth, and are supported by the surrounding soft and hard tissues of the oral cavity. Conventional dentures are removable (removable partial denture or complete denture). However, there are many denture designs, some which rely on bonding or clasping onto teeth or dental implants (fixed prosthodontics). There are two main categories of dentures, the distinction being whether they are used to replace missing teeth on the mandibular arch or on the maxillary arch. Medical uses Dentures do not feel like real teeth, nor do they function like real teeth. Dentures can help people through: * Mastication or chewing ability is improved by replacing edentulous areas with denture teeth. * Aesthetics, because the presence of teeth gives a natural appearance to the face, and wearing a denture to replace missing teeth provides support for the lips and cheeks and corrects the collapsed appearance that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oral Hygiene
Oral hygiene is the practice of keeping one's mouth clean and free of disease and other problems (e.g. bad breath) by regular brushing of the teeth (dental hygiene) and cleaning between the teeth. It is important that oral hygiene be carried out on a regular basis to enable prevention of dental disease and bad breath. The most common types of dental disease are tooth decay (''cavities'', ''dental caries'') and gum diseases, including gingivitis, and periodontitis. General guidelines for adults suggest brushing at least twice a day with a fluoridated toothpaste: brushing last thing at night and at least on one other occasion. Cleaning between the teeth is called interdental cleaning and is as important as tooth brushing. This is because a toothbrush cannot reach between the teeth and therefore only removes about 50% of plaque from the surface of the teeth. There are many tools to clean between the teeth, including floss, tape and interdental brushes; it is up to each individual to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tobacco
Tobacco is the common name of several plants in the genus '' Nicotiana'' of the family Solanaceae, and the general term for any product prepared from the cured leaves of these plants. More than 70 species of tobacco are known, but the chief commercial crop is ''N. tabacum''. The more potent variant ''N. rustica'' is also used in some countries. Dried tobacco leaves are mainly used for smoking in cigarettes and cigars, as well as pipes and shishas. They can also be consumed as snuff, chewing tobacco, dipping tobacco, and snus. Tobacco contains the highly addictive stimulant alkaloid nicotine as well as harmala alkaloids. Tobacco use is a cause or risk factor for many deadly diseases, especially those affecting the heart, liver, and lungs, as well as many cancers. In 2008, the World Health Organization named tobacco use as the world's single greatest preventable cause of death. Etymology The English word ''tobacco'' originates from the Spanish word "tabaco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fitzpatrick Scale
The Fitzpatrick scale (also Fitzpatrick skin typing test; or Fitzpatrick phototyping scale) is a numerical classification schema for human skin color. It was developed in 1975 by American dermatologist Thomas B. Fitzpatrick as a way to estimate the response of different types of skin to ultraviolet (UV) light.Fitzpatrick, T. B. (1975). "Soleil et peau" un and skin ''Journal de Médecine Esthétique'' (in French) (2): 33–34 It was initially developed on the basis of skin color to measure the correct dose of UVA for PUVA therapy, and when the initial testing based only on hair and eye colour resulted in too high UVA doses for some, it was altered to be based on the patient's reports of how their skin responds to the sun; it was also extended to a wider range of skin types.Pathak, M. A.; Jimbow, K.; Szabo, G.; Fitzpatrick, T. B. (1976). "Sunlight and melanin pigmentation". In Smith, K. C. (ed.): ''Photochemical and photobiological reviews'', Plenum Press, New York. pp. 211–39Fitz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenotype
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological properties, its behavior, and the products of behavior. An organism's phenotype results from two basic factors: the expression of an organism's genetic code, or its genotype, and the influence of environmental factors. Both factors may interact, further affecting phenotype. When two or more clearly different phenotypes exist in the same population of a species, the species is called polymorphic. A well-documented example of polymorphism is Labrador Retriever coloring; while the coat color depends on many genes, it is clearly seen in the environment as yellow, black, and brown. Richard Dawkins in 1978 and then again in his 1982 book ''The Extended Phenotype'' suggested that one can regard bird nests and other built structures such as cad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White People
White is a racialized classification of people and a skin color specifier, generally used for people of European origin, although the definition can vary depending on context, nationality, and point of view. Description of populations as "White" in reference to their skin color predates this notion and is occasionally found in Greco-Roman ethnography and other ancient or medieval sources, but these societies did not have any notion of a White or pan-European race. The term "White race" or "White people", defined by their light skin among other physical characteristics, entered the major European languages in the later seventeenth century, when the concept of a "unified White" achieve universal acceptance in Europe, in the context of racialized slavery and unequal social status in the European colonies. Scholarship on race distinguishes the modern concept from pre-modern descriptions, which focused on physical complexion rather than race. Prior to the modern era, no Europe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complexion
Complexion in humans is the natural color, texture, and appearance of the skin, especially on the face. History The word "complexion" is derived from the Late Latin ''complexi'', which initially referred in general terms to a combination of things, and later in physiological terms, to the balance of humors. The four humours were four fluids that were thought to permeate the body and influence its health. The concept was developed by ancient Greek thinkers around 400 BC and developed further by Galen.Matthew Simon, ''Emergent Computation: Emphasizing Bioinformatics'' (Springer, 2005), 145. People were thought to be either of the four temperaments: choleric, melancholic, phlegmatic, or sanguine. During the Middle Ages in Europe, the Latin term ''complexio'' served as the translated form of the Greek word ''crasis'', meaning temperament. The term “temperament” referred to the balance of the qualities of hot, wet, cold, and dry; each human body carried a different mixture of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Risk Factor
In epidemiology, a risk factor or determinant is a variable associated with an increased risk of disease or infection. Due to a lack of harmonization across disciplines, determinant, in its more widely accepted scientific meaning, is often used as a synonym. The main difference lies in the realm of practice: medicine (clinical practice) versus public health. As an example from clinical practice, low ingestion of dietary sources of vitamin C is a known risk factor for developing scurvy. Specific to public health policy, a determinant is a health risk that is general, abstract, related to inequalities, and difficult for an individual to control. For example, poverty is known to be a determinant of an individual's standard of health. Correlation vs causation Risk factors or determinants are correlational and not necessarily causal, because correlation does not prove causation. For example, being young cannot be said to cause measles, but young people have a higher rate of meas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunlight
Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when the Sun is above the horizon. When direct solar radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and radiant heat. When blocked by clouds or reflected off other objects, sunlight is diffused. Sources estimate a global average of between 164 watts to 340 watts per square meter over a 24-hour day; this figure is estimated by NASA to be about a quarter of Earth's average total solar irradiance. The ultraviolet radiation in sunlight has both positive and negative health effects, as it is both a requisite for vitamin D3 synthesis and a mutagen. Sunlight takes about 8.3 minutes to reach Earth from the surface of the Sun. A photon starting at the center of the Sun and changing direction eve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
