Abstract
Sun exposure, fair phototype, and a high common melanocytic nevus (MN) count have been identified as the most important risk factors for melanoma. MN are mainly acquired during childhood, and their relationship to sun exposure, sunburn, and light skin complexion is well documented. The purpose of this study was to investigate how the sun protection attitudes of parents and their offspring affect MN development in children. We designed a cross-sectional study in 828 9-year-old school children. Trained nurses counted the MN on each child's back and arms, depending on their size. Questionnaires filled by children and parents provided information about sun exposure, attitude towards the sun, and sun-protection behaviors. Multivariate analysis showed that the childhood MN count was linked to fair phenotype - fair skin: rate ratio (RR)=3.80, 95% confidence interval (CI)=2.25-6.41; blue/green eyes: RR=1.2, 95% CI=1.11-1.34; blond hair: RR=1.25, 95% CI=1.10-1.41; history of sunburn: RR=1.13, 95% CI=1.03-1.23, seaside sun exposure - RR=1.14, 95% CI=1.01-1.28, and to their parents' behaviors during exposure to the sun - increase in the number of MN when parents used sunscreen: RR=1.23, 95% CI=1.08-1.40; decrease in MN count when parents wore a tee-shirt: RR=0.86, 95% CI=0.79-0.93. In conclusion, fair phenotype and sun exposure are known major risk factors for MN. Parents' behaviors influence their children and appeared in our analysis as another determinant predictor of MN count, being protective against (wearing a tee-shirt when exposed to sun) or increasing the risk (sunscreen use, reflecting higher sun exposure) for childhood MN development.