Melanoma is increasing in most white populations, with the incidence doubling every 10 years.
1 Several phenotypic risk factors have been identified, including the number of melanocytic nevi, the presence of dysplastic nevi, a freckling tendency, the propensity for sunburn, and the number of severe sunburn episodes during childhood.
2 The strongest risk factor for the development of cutaneous melanoma in white populations is the number of acquired melanocytic nevi.
3-6 Most studies found that melanocytic nevi are more common in children with light blue eyes, light skin, and fair hair.
7 Sunlight exposure, as measured by sunburn history and exposure, particularly during vacations and on weekends, is one of the major factors in the development of nevi. The pattern and timing of solar exposure are probably important, and many authors have proved that early exposure, before age 15 years, is associated with later development of melanoma.
8 Irradiation with visible spectral regions could have a role in human beings similar to that in the animal model of tropical fish of the genus
Xiphophorus, in which irradiation with light energy (wavelength >320 nm, including UV-A and visible spectral regions) very early and often in life induced melanomas.
9