Background: Dermoscopic classification of acquired melanocytic nevi (AMN) is based on the evaluation of 3 main criteria-global pattern, pigment distribution, and color.
Objective: To determine whether these features are different in AMN in white people with different skin types (STs) according to the Fitzpatrick classification.
Design: Digital dermoscopic images of AMN were evaluated, and the correlation of the 3 main dermoscopic criteria with patient ST was analyzed.
Setting: Consecutive patients were recruited from 7 pigmented lesion clinics between June 1, 2004, and June 30, 2005. Patients For each patient, the ST (I [always burns, never tans] to IV [rarely burns, tans with ease]) was scored, and 1 representative AMN (defined as the AMN showing a dermoscopic typology that is repeatedly seen in the same patient) was selected and photographed.
Main outcome measures: The distribution of the dermoscopic criteria of AMN in patients with different STs was calculated by univariate analysis. Differences in prevalence were tested using the chi(2) test. The correlation between dermoscopic criteria and ST, adjusted for age, sex, and enrolling center, was evaluated by calculating odds ratios and 95% confidence intervals by logistic regression analysis.
Results: Of 680 included patients, dermoscopic analysis revealed significant differences in the prevalent nevus pattern in the 4 ST groups. Light brown AMN with central hypopigmentation were associated with ST I, and ST IV was associated with the so-called black nevus (P<.001), typified by reticular pattern, central hyperpigmentation, and dark brown coloration. A significant association was also found between multifocal pattern and ST II and ST III.
Conclusions: The dermoscopic nevus type varies according to different ST in white people. This knowledge may have an effect on obtaining for biopsy lesions that exhibit unusual dermoscopic patterns when patient ST is considered.