Interventional three-year longitudinal study of melanocytic naevus development in pre-school children in Dresden, Saxony.

Acquired melanocytic naevi (MN) are considered a risk factor for melanoma. Exposure to ultraviolet light (UV) is the major environmental factor for MN. UV protection is most critical in pre-school children. This 3-year interventional longitudinal study examined 395 3-year-old children attending daycare centres (DCC) in Dresden, Germany. Photo-skin type, eye and hair colour were recorded. DCC were randomly assigned to a control group and a behavioural intervention group. All children had a regular naevus check-up, including digital objective analysis with Dell'Eva-Burroni Dermoscopy Melanoma Image Processing Software (DB-MIPS) technology. Parents of children in the intervention group received additional guidance for sun-protection. The mean total MN counts of both groups at the start of the study period were 7.19 ± 4.55 (intervention) and 6.84 ± 4.63 (control), respectively. There was a significant increase in MN counts for both groups (mean 12.5 and 13.8). Subgroup analysis for skin type, eye colour, and hair colour did not demonstrate a significant influence on MN counts. The DB-MIPS integrated classifier revealed no risky lesions while analysing their patterns. Intervention did not reduce the number of newly acquired MN. MN counts in pre-school children were approximately 5 times higher than expected from previous large studies in Germany. This is the first study in pre-school children using objective digital image analysis of pigmented lesions. No atypical lesions were observed. New approaches to UV protection in pre-school children are now required.