23 April 2013: Join Dr. Robert Dellavalle as he speaks with Dr. Victoria Werth, from the University of Pennsylvania, about the evaluation of the reliability, validity, and responsiveness of the CDASI and the CAT-BM. Validated diseases severity tools for dermatomyositis (DM) in skin are lacking, and this study demonstrates the usefulness of these tools for intra- and inter-rater reliability with a group of 14 DM patients.