Photodermatoses.

Exposure to ultraviolet light is an important factor in precipitating or potentiating a number of cutaneous lesions and may also exacerbate generalized systemic disease activity. Although the role of ultraviolet light is clearly defined in some conditions, its pathogenic role in others is less understood. The approach to this group of diseases in tropical countries differs from that in the Occidental countries. It is important to emphasize the increased sunlight, not only its intensity but its duration throughout the year. On the other hand, the pigmentary variation seen in these areas provides a natural protection against some of these diseases. In some cases, treatment is less sophisticated than in developed countries. In others, the high cost of drugs does not permit their use, and the prophylactic approach is photoprotection.