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November 23, 2009
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 Freckles Main Article |  Glossary |  Freckles Index 

Freckles Glossary of Terms

The following are health and medical definitions of terms that appear in the Freckles article.

Albino: A person with albinism. The term was first applied by the Portuguese to people in West Africa who may have had partial or complete albinism. From the Latin albus for white. See also: Albinism.

Basal cell carcinoma : The most common type of skin cancer , a disease in which the cancer cells resemble the basal cells of the epidermis, the outer layer of the skin.
See the entire definition of Basal cell carcinoma

Benign: Not cancer. Not malignant . A benign tumor does not invade surrounding tissue or spread to other parts of the body. A benign tumor may grow but it stays put (in the same place).
See the entire definition of Benign

Bumps: The raised area of a bump or bruise results from blood leaking from these injured blood vessels into the tissues as well as from the body's response to the injury. A purplish, flat bruise that occurs when blood leaks out into the top layers of skin is referred to as an ecchymosis.
See the entire definition of Bumps

Cancer: An abnormal growth of cells which tend to proliferate in an uncontrolled way and, in some cases, to metastasize (spread).
See the entire definition of Cancer

Carcinoma: Cancer that begins in the skin or in tissues that line or cover body organs. For example, carcinoma can arise in the breast , colon, liver, lung, prostate, and stomach.
See the entire definition of Carcinoma

Cell: The basic structural and functional unit in people and all living things. Each cell is a small container of chemicals and water wrapped in a membrane .
See the entire definition of Cell

Condition: The term "condition" has a number of biomedical meanings including the following:

  1. An unhealthy state, such as in "this is a progressive condition."
  2. A state of fitness, such as "getting into condition."
  3. Something that is essential to the occurrence of something else; essentially a "precondition."
  4. As a verb: to cause a change in something so that a response that was previously associated with a certain stimulus becomes associated with another stimulus; to condition a person, as in behavioral conditioning.

Cryosurgery: Treatment performed with an instrument that freezes and destroys abnormal tissue.

Dermatologist: A doctor who specializes in the diagnosis and treatment of skin problems.

Ephelides: The plural of ephelis, a type of freckle. Ephelis and ephelides are among the many medical terms that are rarely, if ever, encountered outside of medicine.

Ephelis: A form of freckle . A flat red or light-brown spot on the skin that typically appears during the sunny months and fades in the winter. They are most often found in people with light complexions and in some families, they are an hereditary ( genetic ) trait . The regular use of sunscreen during times of sun exposure helps to suppress the appearance of the ephelis-type freckle.
See the entire definition of Ephelis

Epidermis: The upper or outer layer of the two main layers of cells that make up the skin . The epidermis is mostly made up of flat, scale-like cells called squamous cells . Under the squamous cells are round cells called basal cells. The deepest part of the epidermis also contains melanocytes. These cells produce melanin , which gives the skin its color.
See the entire definition of Epidermis

Freckle: A flat circular spot on the skin about the size of the head of a nail that develops after repeated exposure to sunlight, particularly in someone of fair complexion. Freckles may be red, yellow, tan, light-brown, brown, or black. They are always darker than the skin around them since they are due to deposits of the dark melanin , a dark pigment .
See the entire definition of Freckle

Freckles: See: Freckle.

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Genetic: Having to do with genes and genetic information.

Health: As officially defined by the World Health Organization, a state of complete physical, mental, and social well-being, not merely the absence of disease or infirmity.

Heredity: Genetic transmission from parent to child.

Laser: A powerful beam of light that can produce intense heat when focused at close range. Lasers are used in medicine in microsurgery, cauterization, for diagnostic purposes, etc. For example, lasers are employed in microsurgery to cut tissue and remove tissue.
See the entire definition of Laser

Lentigines: When there is one lentigo, there are usually more lentigines.

Lentigo: A type of freckle that is a small tan, brown, or black spot which tends to be darker than the usual (ephelis-type) freckle and which do not fade in the winter. This kind of spot is referred to as lentigo simplex. Although lentigines may be part of a genetic disorder, for the most part they are just isolated and unimportant spots. (The genetic disorder in which lentigines occur is called the LEOPARD syndrome.)
See the entire definition of Lentigo

Liquid nitrogen: Nitrogen in a liquid state. Liquid nitrogen is supercool -- about 200 degrees Celsius (320 degrees Fahrenheit ) below zero -- and is used for cryopreservation , cryosurgery , and cryomedicine.
See the entire definition of Liquid nitrogen

Liver: An organ in the upper abdomen that aids in digestion and removes waste products and worn-out cells from the blood. The liver is the largest solid organ in the body. The liver weighs about three and a half pounds (1.6 kilograms). It measures about 8 inches (20 cm) horizontally (across) and 6.5 inches (17 cm) vertically (down) and is 4.5 inches (12 cm) thick.


See the entire definition of Liver

Malignant: 1. Tending to be severe and become progressively worse, as in malignant hypertension. 2. In regard to a tumor, having the properties of a malignancy that can invade and destroy nearby tissue and that may spread (metastasize) to other parts of the body.
See the entire definition of Malignant

Melanin: A skin pigment (substance that gives the skin its color). Dark-skinned people have more melanin than light- skinned people. Melanin also acts as a sunscreen and protects the skin from ultraviolet light.
See the entire definition of Melanin

Melanoma : The most dangerous form of skin cancer, a malignancy of the melanocyte, the cell that produces pigment in the skin. Melanoma is most common in people with fair skin, but can occur in people with all skin colors. Most melanomas present as a dark, mole-like spot that spreads and, unlike a mole, has an irregular border. The tendency toward melanoma may be inherited, and the risk increases with overexposure to the sun and sunburn.
See the entire definition of Melanoma

Metabolism: The whole range of biochemical processes that occur within us (or any living organism). Metabolism consists both of anabolism and catabolism (the buildup and breakdown of substances, respectively). The term is commonly used to refer specifically to the breakdown of food and its transformation into energy.

Mind: That which thinks, reasons, perceives, wills, and feels. The mind now appears in no way separate from the brain. In neuroscience, there is no duality between the mind and body. They are one.

Nail: In medicine, there are two types of nails. One is just a plain old metal nail used to hold 2 or more pieces of bone together, for example, after a fracture. The other type of nail is the horny plate on the end of the finger or toe. Each nail anatomically has a body, lateral nail folds (on the sides), a lunula (the little moon-shaped feature at the base), and a proximal skin fold (at the base).
See the entire definition of Nail

Nitrogen: Element number 7, a colorless, odorless, tasteless gas that is biologically important. Nitrogen is a constituent of protein and nucleic acids and is present in all living cells. Nitrogen does not support respiration and is fatal if breathed alone, because of the lack of oxygen . Nitrogen is soluble in the blood and body fluids and, when released as bubbles of gas, can have serious or even fatal consequences.
See the entire definition of Nitrogen back to top

Pigment: A substance that gives color to tissue. Pigments are responsible for the color of skin, eyes, and hair.

Pigmentation: The coloring of the skin, hair, mucous membranes, and retina of the eye.
See the entire definition of Pigmentation

Prescription: A physician's order for the preparation and administration of a drug or device for a patient. A prescription has several parts. They include the superscription or heading with the symbol "R" or "Rx", which stands for the word recipe (meaning, in Latin, to take); the inscription, which contains the names and quantities of the ingredients; the subscription or directions for compounding the drug; and the signature which is often preceded by the sign "s" standing for signa (Latin for mark), giving the directions to be marked on the container.

Range: In medicine and statistics, the difference between the lowest and highest numerical values. For example, if five premature infants are born weighing two, three, four, four, and five pounds respectively, the range of their birth weights is two to five pounds.

Section: 1) In anatomy, a slice of tissue. A biopsy obtained by surgery is usually sectioned (sliced), and these sections are inspected under a microscope. 2) In obstetrics, short for Caesarian section. 3) In surgery, the division of tissue during an operation.

Sign: Any objective evidence of disease. Gross blood in the stool is a sign of disease. It can be recognized by the patient, doctor, nurse, or others. In contrast, a symptom is, by its nature, subjective. Abdominal pain is a symptom. It is something only the patient can know.
See the entire definition of Sign

Skin: The skin is the body's outer covering. It protects us against heat and light, injury, and infection. It regulates body temperature and stores water, fat, and vitamin D. Weighing about 6 pounds, the skin is the body's largest organ. It is made up of two main layers; the outer epidermis and the inner dermis.


See the entire definition of Skin

Skin color: The color of skin which is complexly determined. Skin color depends on many factors including reddening caused by inflammation , the hemoglobin level in the blood, and the darkening caused by increased deposition of the pigment melanin . Melanin itself is a polymer that comes in two types -- a red-yellow form known as pheomelanin and a black-brown form known as eumelanin.
See the entire definition of Skin color

Sunburn: Sunburn is an inflammation of the skin that develops in response to exposure to ultraviolet (UV) radiation from the sun or from tanning beds and booths that emit UV radiation . Sunburn is manifested by reddened, painful skin that may develop blisters.
See the entire definition of Sunburn

Sunscreen: A substance that blocks the effect of the sun's harmful rays. Using lotions that contain sunscreens can reduce the risk of skin cancer, including melanoma.

Syndrome: A set of signs and symptoms that tend to occur together and which reflect the presence of a particular disease or an increased chance of developing a particular disease.
See the entire definition of Syndrome

Trait: In genetics, a trait refers to any genetically determined characteristic. In technical terms, a genetic trait is amenable to segregation analysis rather than quantitative analysis.
See the entire definition of Trait

Twin: One of two children produced in the same pregnancy and born during the same birth process.
See the entire definition of Twin back to top

 Freckles Main Article |  Glossary |  Freckles Index 




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Freckles

What is photosensitivity?

Photosensitivity (or sun sensitivity) is inflammation of the skin induced by the combination of sunlight and certain medications or substances. This causes redness (erythema) of the skin and may look similar to sunburn.

Generally, these reactions can be divided into two mechanisms, 1) phototoxic reactions and 2) photoallergic reactions. Phototoxic drugs are much more common than photoallergic drugs.

What is the difference between a photoallergic and a phototoxic reaction?

Phototoxic reactions

In phototoxic reactions, the drug may become activated by exposure to sunlight and cause damage to the skin. The skin's appearance resembles sunburn, and the process is generally acute (has a fast onset). Ultraviolet A (UVA) radiation is most commonly associated with phototoxicity, but ultraviolet B (UVB) and visible light may also contribute to this reaction.

A phototoxic reacti...

Read the Sun-Sensitive Drugs (Photosensitivity to Drugs) article »










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