photosensitization

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Related to secondary photosensitization: primary photosensitization

photosensitization

 [fo″to-sen″sĭ-tĭ-za´shun]
the development of abnormally heightened reactivity of the skin or eyes to sunlight; it can be caused by a wide variety of drugs and chemicals. phototoxic reactions occur when a given drug absorbs ultraviolet radiation from the sun and a sunburnlike response occurs in a short period of time. Within hours there is a burning sensation of the exposed skin, followed by redness and swelling. Within a day or two the skin becomes heavily pigmented and begins to peel; a severe reaction can cause scarring. Phototoxic reactions are more likely to occur in light-skinned persons than in those with darkly pigmented skin that can block harmful radiation.

Photoallergic reactions occur after an initial exposure to the drug or chemical which triggers the production of antibodies. On second exposure a skin eruption appears and there may be intense itching. It is possible for the eruption to appear on unexposed areas of skin as well as exposed areas. There is a long list of drugs that can cause this type of reaction; antineoplastics, antimicrobials, diuretics, hypoglycemic agents, and even antihistamines may trigger it in certain individuals.

pho·to·sen·si·ti·za·tion

(fō'tō-sen-si-ti-zā'shŭn),
1. Sensitization of the skin to light, usually due to the action of certain drugs, plants, or other substances; may occur shortly after administration of the drug (phototoxic sensitivity), or may occur only after a latent period of from days to months (photoallergic sensitivity, or photoallergy).

photosensitization

/pho·to·sen·si·ti·za·tion/ (-sen″sĭ-tĭ-za´shun) development of abnormally heightened reactivity of the skin or eyes to sunlight.

photosensitization

(fō′tō-sĕn′sĭ-tĭ-zā′shən)
n.
The act or process of inducing photosensitivity.

photosensitization

[-sen′sitīzā′shən]
Etymology: Gk, phos, light; L, sentire, to feel
the process of rendering an organism sensitive to the effects of light. photosensitizer, n.

pho·to·sen·si·ti·za·tion

(fō'tō-sen'si-tī-zā'shŭn)
1. Sensitization of the skin to light, usually due to the action of some drugs, plants, or other substances; may occur shortly after administration of the drug (phototoxic sensitivity), or may occur only after a latent period of days to months (photoallergic sensitivity, or photoallergy).

photosensitization,

n skin condition marked by heightened sensitivity to artificial and natural light. May occur as a side effect of some essential oils and other treatments.

photosensitization

the development of abnormally heightened reactivity of the skin to sunlight. In food animals the principal photodynamic agents are porphyrins and phylloerythrin. The principal clinical manifestations are as dermatitis and conjunctivitis. There may be an accompanying hepatic insufficiency or porphyrinuria. See liver dysfunction, photosensitive dermatitis. Called also light sensitization.
There is a long list of drugs that can cause photosensitization reactions. Antineoplastics, antimicrobials, diuretics, hypoglycemic agents, and even antihistamines are capable of triggering photosensitivity reactions in certain individuals.

inherited photosensitization
in Corriedale and Southdown sheep is caused by an inherited liver transport defect. The liver is histologically normal but phylloerythrin excretion is impeded. Photosensitive dermatitis appears as soon as the lambs begin to eat grass.
primary photosensitization
caused by the ingestion of exogenous photosensitizing agents such as dianthrone derivatives (e.g. hypericin, fagopyrin), furanocoumarins, perloline, phenothiazine, rose bengal.
secondary photosensitization
secondary to hepatic cell damage, biliary obstruction leading to the accumulation in the body of phylloerythrin, a metabolic end-product of chlorophyll.