Validation of a Photonumeric Scale for Evaluation of Telangiectasia in Rosacea

ABSTRACT Background Telangiectasia is a prominent feature of rosacea leading to a high demand for effective treatment. To ensure consistent clinical and scientific evaluations and assess treatment response accurately, standardized assessment tools are necessary for grading the severity of telangiectasia. However, no validated grading scales for this condition are currently available. Aim To develop and validate a photonumeric scale for assessing the severity of telangiectasia in rosacea patients. Methods The five‐point photonumeric Telangiectasia in Rosacea Severity Assessment (TRoSA) scale was developed for the severity of telangiectasia in rosacea. Sixteen experts participated in the validation process, evaluating 50 images of rosacea patients in two rounds. Interrater and intrarater reliability were analyzed using the intraclass correlation coefficient (ICC) and weighted kappa, respectively. Results Interrater reliability was found to be “almost perfect” in both validation rounds (Round 1: ICC 0.847; Round 2: ICC 0.828). The mean weighted kappa indicated “substantial” intrarater reliability between the two rounds with a weighted kappa of 0.719. A bubble plot of the two rounds illustrated a diagonal order, confirming the consistency of the intrarater agreement. Conclusions The TRoSA scale demonstrated high interrater and intrarater reliability indicating that it is a consistent and reproducible tool for grading the severity of telangiectasia in rosacea. This scale can standardize clinical assessments, assisting in diagnosis, treatment planning, and evaluation of therapeutic efficacy.