In several studies from northern Europe, north America and Australia, melanocytic nevi are correlated with pigmentary traits and with intense sun exposure in a way similar to malignant melanoma. However, it is unclear if these data can be extrapolated to populations in other geographic locations and with different prevalent phenotypes. Our study was conducted among schoolchildren aged 13-14 years in 16 Italian cities. The parents of 3,127 children of a total of 3,160 (99%) consented to our study. A structured questionnaire was used to collect information about sun exposure and lifetime history of sunburns. Children were also examined by trained dermatologists to assess pigmentary traits and to make a count of melanocytic nevi. The median nevus density was higher among boys than girls. Areas that are usually chronically exposed to the sun exhibited a higher density of nevi compared to intermittently and rarely exposed areas. A higher density of nevi was found in children with lighter skin, blond hair and blue eyes. Red-haired children had a remarkably lower nevus density compared to the other color categories. The density of nevi increased with an increased number of reported episodes of sunburns. The results concerning nevi >6 mm in diameter paralleled those obtained for the total nevus density. However, at variance with total nevus density, a significant relation was also observed between larger nevi and freckling. Our study confirms that, in Italian schoolchildren, there is a relation between pigmentary traits, history of sunburns and the density of melanocytic nevi. Melanocytic nevi and malignant melanoma share a similar risk factor profile. © 2002 Wiley-Liss, Inc.
Key words: melanocytic nevi; malignant melanoma; sunburns; pigmentary traits; epidemiology; South European populationA large number of common melanocytic nevi and the presence of large atypical nevi are strongly associated with cutaneous malignant melanoma. [1][2][3][4][5][6] The biologic correlates of such an association are still poorly understood, but it is plausible that factors that affect the density of melanocytic nevi may also influence the development of malignant melanoma later in life. Risk factors for malignant melanoma have been widely explored in epidemiologic studies and, besides the number of nevi, include pigmentary traits, e.g., light skin and hair color, propensity to sunburns and indicators of intense and intermittent exposure to solar ultraviolet (UV) radiation especially during early life. 7-8 A number of epidemiologic studies confirm that the number of acquired melanocytic nevi is correlated with pigmentary traits, similar to those associated with malignant melanoma, and with intense sun exposure and history of sunburns. 9 -19 Data concerning factors associated with melanocytic nevi have been mostly derived from populations in northern Europe, north America and Australia, and it is unclear if these data can be extrapolated to populations in other geographic locations and with different prevalent phenotypes. The aim of our s...