Automated analysis of the McKenzie test through color slide digitization and processing.

: The McKenzie test is performed to compare the antiinflammatory activity of topical corticosteroids. Each drug induces a local whiteness of the skin called blanching. The blanchings are classically evaluated on the basis of visual score. This paper proposes a new blanching index and a methodology for designing such an index by digitizing and processing color slides. Several indices derived from classical color models are proposed and compared to the visual scores. This work demonstrates the significant improvement of quantitation derived from digitized images with respect to the observer assessment. The difference of chromatic green between the blanching patch and the surrounded healthy skin is proposed for analysis of the McKenzie test.