The Ostomy Skin Tool is a standardized measuring instrument for assessing the extent and severity of peristomal skin change in terms of discolouration (D), erosion (E), and tissue overgrowth (T) (DET). The reliability and validity of this tool has been determined in a previous study. The purpose of this article is to highlight the study's most important findings, and to demonstrate the usefulness of the DET score by evaluating three examples of peristomal skin changes. Additionally, a simplified categorical severity scale (defining 'mild', 'moderate', and 'severe' conditions) is introduced that may improve clinical interpretation of the DET score. It is reasonable to conclude that the DET score may empower the ostomy care nurse with an evidence-based platform to make qualified decisions on evaluation and treatment of peristomal skin disorders.