Epidemiology of digital epiluminescence microscopy features of acquired melanocytic naevi

This study addressed the independent association of past and recent sun exposure indicators and other host factors with the prevalence of major digital epiluminescence microscopy (D-ELM) features such as the pigment network (PN), brown globules (BGs), and pigment dots (PDs) in acquired melanocytic naevi. In a consecutive series of 189 patients (median age 28 years; range 10-73 years) with one or more naevi as diagnosed on D-ELM, we evaluated 35 solitary lesions and one naevus randomly selected from each of the 154 patients with multiple lesions. D-ELM images were classified for the presence or absence of PN, BGs and PDs on two blind readings. Data analysis was based on multiple logistic regression. Patient age was positively associated with PN and inversely associated with BGs. The probability of PN increased with more than 110 days since last exposure to the sun, whereas a rapid decrease for BGs and PDs was observed after approximately 1 month. PDs were significantly more likely among lesions with 6-10 h/day of recent exposure. Sex, total lifetime hours of exposure, sunbed use, skin type and colour of hair exerted no effect. In conclusion, major D-ELM features appeared to differ in their relationship with sun exposure indicators.