Selective sunscreen application on nevi: frequency and determinants of a wrong sun-protective behaviour

BACKGROUND: Sunscreen use is generally recommended in order to prevent skin cancer but erroneous patterns of use were reported, including the selective application on melanocytic nevi. OBJECTIVE: To assess prevalence and determinants of selective sunscreen application on nevi and participants' behavioural risk profile overall. METHODS: A multilingual, dichotomous, funnel-designed questionnaire about sun exposure/protection habits and perceived nevus count was administered to patients attending five Dermatology Departments in three countries (Italy, Austria and France). Multivariate logistic regression models were used to determine independent predictors of each answer. RESULTS: Among the 1816 subjects surveyed (59.3% females, age 14-90 (median 45) years, 44.7% Italians), 1273 (70.1%) reported intentional sun exposure and 1109/1273 (87.1%) reported sunscreen use. Among the latter, 1086 (97.9%) stated they have moles on their skin. Fifty-one/1086 (4.7%) reported selective sunscreen application on nevi. Reported information sources were: dermatologist (49.0%), personal belief (31.4%), relative/friend (7.8%), media (7.8%), paediatrician (2.0%) and general practitioner (2.0%). Increasing age (P < 0.05) and being Italian (P < 0.001) were independent predictors of selective sunscreen application on nevi. Sun-seeking behaviours were predicted by decreasing age, female sex and being Italian. CONCLUSION: Selective sunscreen application on nevi was more common than expected. It is of concern that this was recommended mostly by physicians. There is a need to educate patients, non-expert clinicians, media and the sunscreen industry on this matter. Tan patients presenting with halo nevi should be questioned about this behaviour in order to avoid false positive diagnoses