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tretinoin, Retin A Glossary of Terms

The following are health and medical definitions of terms that appear in the tretinoin, Retin A article.

Acne: Localized skin inflammation as a result of overactivity of the oil glands at the base of hair follicles. Acne happens when oil (sebaceous) glands come to life around puberty, when these glands are stimulated by male hormones that are produced in the adrenal glands of both boys and girls.
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Breast : The breast refers to the front of the chest or, more specifically, to the mammary gland. The mammary gland is a milk producing gland. It is composed largely of fat. Within the mammary gland is a complex network of branching ducts. These ducts exit from sac-like structures called lobules, which can produce milk in females. The ducts exit the breast at the nipple.
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Breast milk: Milk from the breast . Human milk contains a balance of nutrients that closely matches infant requirements for brain development, growth and a healthy immune system . Human milk also contains immunologic agents and other compounds that act against viruses , bacteria , and parasites. Since an infant's immune system is not fully developed until age 2, human milk provides a distinct advantage over formula.
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FDA: The Food and Drug Administration, an agency within the U.S. Public Health Service, which is a part of the Department of Health and Human Services.
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Fetus: The unborn offspring from the end of the 8th week after conception (when the major structures have formed) until birth. Up until the eighth week, the developing offspring is called an embryo.

Generic: 1. The chemical name of a drug. 2. A term referring to the chemical makeup of a drug rather than to the advertised brand name under which the drug may be sold. 3.A term referring to any drug marketed under its chemical name without advertising.

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Infant: A child up to 2 years (24 months) of age.
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Inflammation: A basic way in which the body reacts to infection , irritation or other injury, the key feature being redness, warmth, swelling and pain . Inflammation is now recognized as a type of nonspecific immune response .
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Lactation: The process of milk production. Human milk is secreted by the mammary glands, which are located within the fatty tissue of the breast . The hormone oxytocin is produced in response to the birth of a new baby, and it both stimulates uterine contractions and begins the lactation process. For the first few hours of nursing, a special fluid called colostrum is delivered, which is especially high in nutrients, fats, and antibodies to protect the newborn from infection. Thereafter the amount of milk produced is controlled primarily by the hormone prolactin, which is produced in response to the length of time the infant nurses at the breast .
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Nursing: 1) Profession concerned with the provision of services essential to the maintenance and restoration of health by attending the needs of sick persons. 2) Feeding a infant at the breast.

Photosensitivity: In medicine, increased sensitivity of the skin to light and other sources of UV. Photosensitivity commonly causes reddening and blistering of the skin with exposure to sunlight and, in time, it heightens the risk of skin cancer. A number of diseases make for photosensitivity, as do scores of prescription and non-prescription drugs. (For details, see Sunburn and Sun-Sensitizing Drugs ).
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Pimples: Small papules or pustules. See: Pimple.

Pregnancy: The state of carrying a developing embryo or fetus within the female body. This condition can be indicated by positive results on an over-the-counter urine test, and confirmed through a blood test, ultrasound, detection of fetal heartbeat, or an X-ray. Pregnancy lasts for about nine months, measured from the date of the woman's last menstrual period (LMP). It is conventionally divided into three trimesters, each roughly three months long.
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Pregnant: The state of carrying a developing fetus within the body.
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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.

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Scaling: Abnormal shedding or accumulation of an upper layer of skin (the stratum corneum ).
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Sensation: In medicine and physiology , sensation refers to the registration of an incoming ( afferent ) nerve impulse in that part of the brain called the sensorium , which is capable of such perception. Therefore, the awareness of a stimulus as a result of its perception by sensory receptors. (Sensory is here synonymous with sensation.)
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Sensitivity: 1. In psychology, the quality of being sensitive. As, for example, sensitivity training, training in small groups to develop a sensitive awareness and understanding of oneself and of ones relationships with others. 2. In disease epidemiology, the ability of a system to detect epidemics and other changes in disease occurrence. 3. In screening for a disease, the proportion of persons with the disease who are correctly identified by a screening test. 4. In the definition of a disease, the proportion of persons with the disease who are correctly identified by defined criteria.

Side effects: Problems that occur when treatment goes beyond the desired effect. Or problems that occur in addition to the desired therapeutic effect.
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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.


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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.
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Therapy: The treatment of disease .
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Topical: Pertaining to a particular surface area. A topical agent is applied to a certain area of the skin and is intended to affect only the area to which it is applied. Whether its effects are indeed limited to that area depends upon whether the agent stays where it is put or is absorbed into the blood stream.
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Vesicles: In dermatology, vesicles are small blisters, most often on the skin. Vesicles also can crop up on the mucous membranes, such as the buccal mucosa (the lining of the mouth).
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tretinoin, Retin A, Atralin, Renova, Avita, Altinac

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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