Dermoscopic changes in melanocytic naevi in children during digital follow-up.

The aim of this study was to investigate the dermoscopic changes in acquired melanocytic naevi in a large paediatric population over an interval of several years. Images of 717 melanocytic naevi were obtained from 160 consecutive patients. Dermoscopic pigment pattern changes were observed in one of two lesions after a follow-up of one year, in 34 of 295 lesions (11.5%) after 2 years, in 40 of 190 lesions (21.1%) after 3 years, in 40 of 141 lesions (28.4%) after 4 years, in 5 of 37 lesions (13.5%) after 5 years, in 12 of 31 lesions (38.8%) after 6 years, and in 7 of 21 lesions (33.3%) after 7 years. Dermoscopic changes were detected in 25.3% of the lesions in patients aged 3-6 years, in 21% of the lesions in patients aged 7-12 years, and in 15.5% of the lesions in patients over 13 years. Main pattern changes consisted of transition from globular to globular-reticular (35 naevi), from globular to reticular (14 naevi) and from globular-reticular to reticular (24 naevi). These results are consistent with the view that melanocytic naevi generally undergo a characteristic transition from a globular pattern to a reticular pattern. Most of the changes are observed in the 3-6 years age group when hormonal and/or environmental factors are not thought to play a role in pattern alterations.