A validation study of scar vascularity and pigmentation assessment using dermoscopy

Vascularity and pigmentation are two important indicators of the maturing status of hypertrophic scars. We used the dermoscope to measure vascularity and pigmentation of hypertrophic scars to examine its validity and reliability.

Eighteen subjects were assessed using the Vancouver Scar Scale (VSS), spectrocolorimeter and dermoscope. Correlations between the measurements by these tools and reliability parameters were examined.

A strong correlation was found between the redness measured by spectrocolorimeter and the RGB redness values of dermoscope pictures (r=0.890). A correlation was found between the lightness measured by spectrocolorimeter and the lightness of dermoscope pictures (r=0.536), and between the lightness by spectrocolorimeter and the blanched dermoscope pictures (r=0.448). The calculated RGB values of redness of the dermoscope correlated with the VSS vascularity score (r=0.625); the transformed VSS pigmentation score correlated with the lightness of the blanched dermoscope pictures (r=0.783). The intra-class correlation coefficient (3, 1) of the dermoscope was 0.980 for the redness measurement and 0.965 for the lightness measurement, while the intra-class correlation coefficient (2, 2) was 0.930 for the dermoscope redness measurement and 0.871 for the dermoscope lightness.

The dermoscope is a promising objective tool for vascularity and pigmentation assessments of hypertrophic scars with good validity and reliability.