Frequency and distribution pattern of melanocytic naevi in Swedish 8-9-year-old children

The naevus profile was examined in a Swedish cohort of 8-9-year-old children; 524/545 individuals (96%) were examined (279 boys and 245 girls). There was a wide variation in the total number of naevi (0-79) and boys had more naevi than girls (median 9 and 7, respectively, p<0.01). No dysplastic naevi were found. Overall, 15/ 524 (3%) had at least one lesion clinically diagnosed as a congenital melanocytic naevus. Boys had more naevi on the face (median 1) and trunk (median 5) than girls (median 0 and 3, respectively, p<0.001). There was no difference in the number of naevi on the legs between the two sexes. The highest counts per unit surface area for both sexes were found on the back, chest and the lateral aspect of the arms, areas intermittently sun-exposed. Children with fair skin and light eye colours had significantly more naevi than those with darker colours but children with red hair had very few naevi. Children with one or more naevi on the buttocks (25%), dorsal surfaces of the feet (11%) or on the scalp (7%) had twice as many naevi in total compared with those without naevi in these regions. Children with naevi in all three regions (0.8%) had four times as many naevi in total. A relationship between total counts and counts on the back or lateral aspect of the arms was found (r2 = 0.59). Either of these two areas might be suitable for predicting total naevus counts.