Photosensitivity to exogenous agents.
OBJECTIVE
To better understand cutaneous photosensitivity reactions, a review of its etiologic factors, clinical characteristics, pathogenesis, and treatment modalities was undertaken.


METHODS
Articles discussing the above aspects of phototoxic and photoallergic reactions were used to demonstrate what is currently known about photoinduced reactions and how to treat them.


RESULTS
Upon interaction of solar UV radiation with the chemical that is present in significant levels on the skin, one of two known reactions may occur in susceptible patients: a phototoxicity and/or photoallergy. Phototoxic and photoallergic reactions can be diagnosed separately on the basis of pathogenesis, clinical characteristics, and histology. Examples of drugs capable of inducing a phototoxic reaction include amiodarone, retinoids, nonsteroidal antiinflammatory agents, diuretics, and antibiotics. Substances known to cause a photoallergic response are fragrances, sunscreens, topical antimicrobials, NSAID, and psychiatric medications, such as chlorpromezine.


CONCLUSIONS
Photoinduced reactions produced by exogenous chemicals are common skin disorders. Definitive therapy requires identifying and removing the offending agent, either the photosensitizing chemical or light. The use of fully protective clothing and a sunscreen of high SPF are important measures when light exposure is inevitable.
Department of Dermatology, Case Western Reserve University, Cleveland, Ohio 44106, USA. lelalanky@hotmail.com
Lela
L
Lankerani
Elma D
ED
Baron
D017454:Dermatitis, Photoallergic / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D017484:Dermatitis, Phototoxic / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D010787:Photosensitivity Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D014466:Ultraviolet Rays / Q000009:adverse effects*