Natural history of naevi: a two?wave study

Background Naevi number changes with age. Thus, a better understanding of naevus biology will shed more light on the genetic and environmental factors involved in melanoma development. Objectives To use two-wave study to understand evolution naevi healthy adults. Methods This is prospective based adult twins from TwinsUK registry (n = 414) who underwent total body counts an interval at least 15 years. A negative binomial hierarchical model two levels, individual twin pair, was used estimate expected count between first second visit, any specific site whole body. The adjusted for age, calendar year height skin type. Results mean age participants 46 years visit 63 (the elapsed time visits 17 years). An increase observed 235 (57%) decrease 166 (40%). difference nine. increased, logarithmic scale, by 0·28 [95% confidence (CI) 0·16–0·40] change incidence rate 32% (95% CI 17–49%). However, over only upper parts body, whereas there no evidence lower parts. Conclusions Naevus increased slightly older ages, but this dependent site. overall previously reported cross-sectional studies has not been confirmed longitudinal study.