The exposure of blood that is temporarily removed from the body to ultraviolet A radiation. This is used to treat several diseases, including pemphigus vulgaris and cutaneous T cell lymphoma.
CAUTION!Patients exposed to photosensitizing agents, such as psoralens in conjunction with ultraviolet light, have an increased risk of melanoma and squamous cell carcinoma. They should be examined regularly so that any developing skin cancers will be detected early.
See also: photochemotherapy
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