Photoprotection.

Sun exposure is the main cause of photocarcinogenesis, photoageing, and photosensitivity; thus, photoprotection is an important issue. In a skin cancer prevention strategy, behavioural measures--eg, wearing sun protective clothes and a hat and reducing sun exposure to a minimum--should be preferred to sunscreens. Often this solution is deemed to be unacceptable in our global, outdoor society, and sunscreens could become the predominant mode of sun protection for various societal reasons (eg, healthiness of a tan, relaxation in the sun). The application of a liberal quantity of sunscreen has been shown to be by far the most important factor for effectiveness of the sunscreen, followed by the uniformity of application and the specific absorption spectrum of the agent used. The sunscreen market--crowded by numerous products--shows various differences worldwide. Nevertheless, sunscreens should not be abused in an attempt to increase time in the sun to a maximum. Controversies about safety of sunscreens and clinical recommendations are discussed.