New Method Of Describing Psoriasis
Physicians created the Psoriasis Area and Severity Index (PASI) in 1978 because they needed an objective and quantitative way to describe the effectiveness of a new psoriasis treatment drug Soriatane (acitretin.) Over the past 3 decades, PASI has become a widely used method for assessing the severity of psoriasis, as well as for judging new psoriasis medications and therapies.
Although the Psoriasis Area and Severity Index has become the gold standard in assessing how new psoriasis treatments are evaluated, it does have some shortcomings. For one, it is too complicated and time-consuming to be practical in most clinical settings. Also, it involves a number of quantizations and approximations. These simplifications are handy in the absence of tools, but why not use tools?! Furthermore, PASI has an element of subjectivity. Increasing objective measures would make the system more consistent from observer to observer, and from time to time by the same observer.
Skinofmine.com has developed a simple system for precisely determining the extent and severity of psoriasis and its progression, based on standard measures and machine learning techniques. We measure the area of psoriasis in square millimeters, using clustering techniques to precisely locate its boundaries. We quantify redness, scaliness, and thickness based upon features in the image. We take scaling, rotation, and translation into account while determining the best alignment of two images for the purpose of visualizing changes over time.
We hope Skin Of Mine quantification tools will prove useful in the monitoring of psoriasis by both patients and doctors.