Drug-induced cutaneous photosensitivity: some drugs warrant routine precautions.

(1) Drug-induced cutaneous photosensitivity is defined as excessive or abnormal skin reactions to light, linked to systemic or topical administration of a drug. (2) The lesions appear after exposure to sunlight or an ultraviolet source, and are limited to or predominate in exposed areas. (3) Some drugs can induce occasionally severe skin burns after moderate exposure to sunlight. Other types of drug-related skin lesion include eczematous or urticarial eruptions, pseudoporphyria, abnormal pigmentation and pseudolichen. Photo-induced or photo-aggravated contact dermatitis can occur after application of a photosensitising drug. (4) Some drugs are particularly photosensitising, such as psoralens, tetracyclines, amiodarone and quinolones. (5) Patients treated with drugs known to cause cutaneous photosensitivity should be warned of the risk of cutaneous reactions on exposure to light and be encouraged to protect their skin from intense exposure to sunlight. (6) The possible responsibility of a drug should be borne in mind when a patient presents with skin lesions with a distribution typical of cutaneous photosensitivity. Drug withdrawal and subsequent avoidance can lead to recovery and avoid recurrences.