2004 Volume 114 Issue 11 Pages 1769-1776
In pemphigus vulgaris, the assessment of disease severity is usually performed arbitrarily. Computer-assisted measurement of the overall area of skin lesions would be useful in the assessment of the severity of pemphigus vulgaris. Because various skin lesions are observed in patients with pemphigus vulgaris, it is not possible to extract lesions simply based on image brightness. The aim of the present study was to extract skin lesions on the back based on red color information using CIE L*a*b* color measurement and Gauss filter with an image analysis program. Active lesions could be extracted at a color difference (ΔE) of 13 or more with a 0.3% point margin of error. We also calculated the ratio of the total area of the skin lesions to that of the normal skin. The ratio did not correlate well with desmoglein titers measured by enzyme-linked immunosorbent assay. Our results indicated that measurement of the area of the skin lesions by image analysis is accurate and could be potentially useful clinically for the objective assessment of disease severity in pemphigus vulgaris.
