Costa Rica is a tropical country having a high sun exposure rate, with a high proportion of its population having pale skin. The most frequent malignant tumor nowadays in men and women is the skin cancer. This is probably due to the high exposure of the people to ultraviolet radiation from the sun since very early ages. Another effect of sun exposure is the photoaging, which is a very common cosmetic reason for seeking dermatological attention. Different factors related with the photobiology of the exposure of the skin to ultraviolet rays are analyzed and a review of chemical and physical sunscreens is presentes, discussing its effect as filters, scattering, absorbents or reflecting agents. Pharmacological properties and prescription characteristics of the sunscreens are discussed with special emphasis to its use in Costa Rica. A skin cancer and photoaging preventive program based in the education of the population is proposed.

Sunscreens; photobiology; skin cancer; photoaging