photosensitization

(redirected from photoallergic sensitivity)
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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

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

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).