A preliminary study for fully automated quantification of psoriasis severity using image mapping

Psoriasis is a common chronic skin disease and it detracts patients’ QoL seriously. Since there has been no known permanent cure so far, controlling appropriate disease condition is necessary and therefore quantification of its severity is important. In clinical, psoriasis area and severity index (PASI) is commonly used for abovementioned purpose, however it is often subjective and troublesome. A fully automatic computer-assisted area and severity index (CASI) was proposed to make an objective quantification of skin disease. It investigates the size and density of erythema based on a digital image analysis, however it does not consider various inadequate effects caused by different geometrical conditions. In this study, we proposed an image alignment method for clinical images and investigated to quantify the severity of psoriasis under the clinical follow-up combined with the definition of CASI