Prevalence of common and atypical melanocytic nevi in young adults and its relationship with sun protection and exposure habits.

Unlabelled: Background: The incidence of melanoma in young adults is rising. The design of appropriate preventive measures requires the analysis of risk factors, including the prevalence of common and atypical melanocytic nevi (MN) and sun protection and exposure habits.

Objectives: To establish the prevalence and density of common and atypical MN in young adults (18-25 yrs) and their relationship with sun exposure and protection habits.

Methods: Cross-sectional descriptive study was undertaken in 535 university students from southern Spain to gather data on: the number, density, body localization, and characteristics of common and atypical nevi; phototype; sunburn history; sun protection and exposure habits; and family history of skin cancer.

Results: Means of 94.28 common MN and 0.06 atypical MN were detected; most MN were ≤2 mm in diameter; MN were more frequently detected on upper (p<0.01) and lower (p<0.0001 limbs in females versus males and on the trunk (p = 0.08) in males versus females. Nevus density was higher in females in all body areas. Sunburns (in the previous summer) were reported by 88.2% of participants, while cream with SPF ≥15 was not used by 75.8%. Mean number of atypical MN was higher in those with low phototypes and a family history of skin cancer.

Conclusions: Mean number of common MN was elevated and atypical MN were associated with a low phototype and a family history of skin cancer. Sunburn history was significantly associated with younger age and with sun exposure between mid-day and 6 pm.