The most extensive study to date, a 1981 survey of nearly 20,000 French males aged 17 to 26, served to disprove many commonly held beliefs about the disorder. In the French study, 100 subjects were found to have<unk> 's nevi, revealing a prevalence of 0.52%. Nevi appeared in one half the subjects before the age of 10, and between ages 10 and 20 in the rest. In one quarter of cases sun exposure seems to have played a role, a number apparently lower than that expected by researchers. Also surprising to researchers was the low incidence (32%) of<unk> 's nevi above the nipples, for it had generally been believed that the upper chest and shoulder area was the predominant site of occurrence. Pigmentation was light brown in 75% of cases (note: subjects were Caucasian), and average size of the<unk>  was 125 cm2 (19 in2).
Becker's nevus
Hori's nevus
Spitz nevus
Ink spot lentigo
Halo nevus
Smoker's melanosis
Riehl melanosis
Forchheimer spots