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Hypopigmentation
Hypopigmentation is characterized specifically as an area of Human skin, skin becoming lighter than the baseline skin color, but not completely devoid of skin pigment, pigment. This is not to be confused with depigmentation, which is characterized as the absence of all pigment. It is caused by melanocyte or melanin depletion, or a decrease in the amino acid tyrosine, which is used by melanocytes to make melanin. Some common genetic causes include mutations in the tyrosinase gene or OCA2 gene. As melanin pigments tend to be in the skin, eye, and hair, these are the commonly affected areas in those with hypopigmentation. Hypopigmentation is common and approximately one in twenty have at least one hypopigmented macule. Hypopigmentation can be upsetting to some, especially those with darker skin whose hypopigmentation marks are seen more visibly. Most causes of hypopigmentation are not serious and can be easily treated. Presentation Associated conditions It is seen in: * Albinism * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postinflammatory Hypopigmentation
Postinflammatory hypopigmentation is a cutaneous condition characterized by decreased pigment in the skin following inflammation of the skin.Marks, James G; Miller, Jeffery (2006). ''Lookingbill and Marks' Principles of Dermatology'' (4th ed.). Elsevier Inc. . Signs and symptoms Hypopigmentation, Hypopigmented lesions can range in color from hypopigmentation to depigmentation, and their size, form, and primary inflammatory dermatosis frequently correspond with each other. Complete depigmentation is more noticeable in people with darker skin and is frequently observed in cases of discoid lupus erythematosus and severe atopic dermatitis. When pigmentary alterations occur with the initial inflammatory lesions, the diagnosis is often easy to make. Hypopigmentation, however, may be the only characteristic in certain situations, in which the inflammatory phase is not always evident. Little white macules that resemble the size and form of the laser spot are indicative of pigmentary chang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanin
Melanin (; ) is a family of biomolecules organized as oligomers or polymers, which among other functions provide the pigments of many organisms. Melanin pigments are produced in a specialized group of cells known as melanocytes. There are five basic types of melanin: eumelanin, pheomelanin, neuromelanin, allomelanin and pyomelanin. Melanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino acid tyrosine is followed by polymerization. Pheomelanin is a cysteinated form containing poly benzothiazine portions that are largely responsible for the red or yellow tint given to some skin or hair colors. Neuromelanin is found in the brain. Research has been undertaken to investigate its efficacy in treating neurodegenerative disorders such as Parkinson's. Allomelanin and pyomelanin are two types of nitrogen-free melanin. The phenotypic color variation observed in the epidermis and hair of mammals is primarily determi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tinea Versicolor
Tinea versicolor (also pityriasis versicolor) is a condition characterized by a skin eruption on the trunk and proximal extremities. The majority of tinea versicolor is caused by the fungus '' Malassezia globosa'', although '' Malassezia furfur'' is responsible for a small number of cases. These yeasts are normally found on the human skin and become troublesome only under certain conditions, such as a warm and humid environment, although the exact conditions that cause initiation of the disease process are poorly understood. The condition pityriasis versicolor was first identified in 1846. Versicolor comes from the Latin ' 'to turn' + ''color''. It is commonly referred to as Peter Elam's disease in many parts of South Asia. Signs and symptoms The signs of this condition include: * Occasional fine scaling of the skin producing a very superficial ash-like scale * Pale, dark tan, or pink in color, with a reddish undertone that can darken when the patient is overheated, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pityriasis Alba
Pityriasis alba is a skin condition, a type of dermatitis, commonly seen in children and young adults as dry, fine-scaled, pale patches on the face. It is self-limiting and usually only requires use of moisturizer creams. The condition is so named for the fine scaly appearance initially present ( pityriasis), and alba (Latin for white) refers to the pallor of the patches that develop. The patches are not totally depigmented. Signs and symptoms The dry scaling appearance is most noticeable during the winter as a result of dry air inside people's homes. During the summer, tanning of the surrounding normal skin makes the pale patches of pityriasis alba more prominent. Individual lesions develop through 3 stages and sometimes are itchy: # Raised and red – although the redness is often mild and not noticed by parents # Raised and pale # Smooth flat pale patches Lesions are round or oval raised or flat, of 0.5–2 cm in size although may be larger if they occur on the body (up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenylketonuria
Phenylketonuria (PKU) is an inborn error of metabolism that results in decreased metabolism of the amino acid phenylalanine. Untreated PKU can lead to intellectual disability, seizures, behavioral problems, and mental disorders. It may also result in a musty smell and lighter skin. A baby born to a mother who has poorly treated PKU may have heart problems, a small head, and low birth weight. Phenylketonuria is an inherited genetic disorder. It is caused by mutations in the '' PAH'' gene, which can result in inefficient or nonfunctional phenylalanine hydroxylase, an enzyme responsible for the metabolism of excess phenylalanine. This results in the buildup of dietary phenylalanine to potentially toxic levels. It is autosomal recessive, meaning that both copies of the gene must be mutated for the condition to develop. The two main types are classic PKU and variant PKU, depending on whether any enzyme function remains. Those with one copy of a mutated gene typically do not ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Idiopathic Guttate Hypomelanosis
Idiopathic guttate hypomelanosis is characterised by multiple small whitish flat spots. They are typically irregular, well defined and frequently appear on the arms, legs, and faces of older people. It occurs in up to 80% of people over 70 years old. Females may notice it at a younger age than males. See also * List of cutaneous conditions * Skin lesion 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 ... References Disturbances of human pigmentation {{Cutaneous-condition-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitiligo
Vitiligo (, ) is a chronic autoimmune disorder that causes patches of skin to lose pigment or color. The cause of vitiligo is unknown, but it may be related to immune system changes, genetic factors, stress, or sun exposure, and susceptibility to it may be affected by regional environmental risk factors, especially early in life. Treatment options include topical medications, light therapy, surgery and cosmetics. The condition causes patches of a light peachy color of any size, which can appear on any place on the body; in particular, nonsegmental vitiligo, the common form, tends to progress, affecting more of the skin over time. Vitiligo spots on the skin can also vary in pigmentation over long periods, although they will stay in relatively the same areas. Signs and symptoms The only sign of vitiligo is the presence of pale patchy areas of depigmented skin which tend to occur on the extremities. Some people may experience itching before a new patch appears. The patches ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leucism
Leucism () is a wide variety of conditions that result in partial loss of pigmentation in an animal—causing white, pale, or patchy coloration of the skin, hair, feathers, scales, or cuticles, but not the eyes. It is occasionally spelled ''leukism''. Some genetic conditions that result in a "leucistic" appearance include piebaldism, Waardenburg syndrome, vitiligo, Chédiak–Higashi syndrome, flavism, isabellinism, xanthochromism, axanthism, amelanism, and melanophilin mutations. Pale patches of skin, feathers, or fur (often referred to as " depigmentation") can also result from injury. Details ''Leucism'' is often used to describe the phenotype that results from defects in pigment cell differentiation and/or migration from the neural crest to skin, hair, or feathers during development. This results in either the entire surface (if all pigment cells fail to develop) or patches of body surface (if only a subset are defective) having a lack of cells that can make pigm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leprosy
Leprosy, also known as Hansen's disease (HD), is a Chronic condition, long-term infection by the bacteria ''Mycobacterium leprae'' or ''Mycobacterium lepromatosis''. Infection can lead to damage of the Peripheral nervous system, nerves, respiratory tract, skin, and eyes. This nerve damage may result in a lack of ability to feel pain, which can lead to the loss of parts of a person's Appendicular skeleton, extremities from repeated injuries or infection through unnoticed wounds. An infected person may also experience muscle weakness and poor eyesight. Leprosy symptoms may begin within one year, but for some people symptoms may take 20 years or more to occur. Leprosy is spread between people, although extensive contact is necessary. Leprosy has a low pathogenicity, and 95% of people who contract or who are exposed to ''M. leprae'' do not develop the disease. Spread is likely through a cough or contact with fluid from the nose of a person infected by leprosy. Genetic factors and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angelman Syndrome
Angelman syndrome (AS) is a genetic disorder that affects approximately 1 in 15,000 individuals. AS impairs the function of the nervous system, producing symptoms, such as severe intellectual disability, developmental disability, limited to no functional speech, balance and movement problems, seizures, hyperactivity, and sleep problems. Physical symptoms include a small head and a specific facial appearance. Additionally, those affected usually have a happy personality and have a particular interest in water. Angelman syndrome involves genes that have also been linked to 1–2% of autism spectrum disorder cases. Epidemiology Though the prevalence of Angelman syndrome is not precisely known, there are some estimates. The best data available are from studies of school age children, ages 6–13 years, living in Sweden and from Denmark where the diagnosis of AS children in medical clinics was compared to an 8-year period of about 45,000 births. The Swedish study showed an AS preva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leukoderma
Vitiligo (, ) is a chronic autoimmune disorder that causes patches of skin to lose pigment or color. The cause of vitiligo is unknown, but it may be related to immune system changes, genetic factors, stress, or sun exposure, and susceptibility to it may be affected by regional environmental risk factors, especially early in life. Treatment options include topical medications, light therapy, surgery and cosmetics. The condition causes patches of a light peachy color of any size, which can appear on any place on the body; in particular, nonsegmental vitiligo, the common form, tends to progress, affecting more of the skin over time. Vitiligo spots on the skin can also vary in pigmentation over long periods, although they will stay in relatively the same areas. Signs and symptoms The only sign of vitiligo is the presence of pale patchy areas of depigmented skin which tend to occur on the extremities. Some people may experience itching before a new patch appears. The patches a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piebaldism
Piebaldism refers to the absence of mature melanin-forming cells (melanocytes) in certain areas of the skin and hair. It is a rare autosomal dominant disorder of melanocyte development.James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. . Common characteristics include a congenital white forelock, scattered normal pigmented and hypopigmented macules and a triangular shaped depigmented patch on the forehead. There is nevertheless great variation in the degree and pattern of presentation, even within affected families. In some cases, piebaldism occurs together with severe developmental problems, as in Waardenburg syndrome and Hirschsprung's disease. Piebaldism has been documented to occur in all races, and is found in nearly every species of mammal. The condition is very common in mice, rabbits, dogs, sheep, deer, cattle and horses—where selective breeding has increased the incidence of the mutation� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
