Sensitivity and Specificity of Reflectance Confocal Microscopy and Dermoscopy in Assessing Vitiligo Staging

BACKGROUND: Accurate staging of vitiligo is essential for effective treatment. Current staging primarily relies on clinical manifestations, patients' subjective reports, and physicians' assessments, which may introduce inaccuracies. Reflectance confocal microscopy (RCM) and dermoscopy are auxiliary diagnostic tools in dermatology that support the diagnosis and differentiation of vitiligo; they also assist in staging and evaluating therapeutic efficacy. AIMS: This study aimed to compare the sensitivity and specificity of RCM and dermoscopy in vitiligo staging, providing a more reliable reference for clinical application. METHODS: A retrospective review was conducted of clinical and imaging data from 218 patients with vitiligo who attended the Department of Dermatology at Wuhan No. 1 Hospital between December 2023 and November 2024. Clinical assessment methods-clinical features, Vitiligo Disease Activity score, Wood's lamp examination, and Koebner phenomenon-served as the reference standard for staging. Blinded evaluators independently conducted staging using RCM and dermoscopy. Each modality's sensitivity and specificity were calculated. RESULTS: Staging results based on RCM and dermoscopy showed strong concordance with clinical evaluation; Kappa values were 0.74 and 0.718, respectively (p < 0.01). The positive percent agreement and negative percent agreement of RCM staging with clinical assessment were 94.16% and 78.12%, respectively; those metrics for dermoscopy were 87.01% and 89.06%. RCM demonstrated significantly higher sensitivity than dermoscopy (p = 0.013), whereas dermoscopy showed significantly higher specificity than RCM (p = 0.039). CONCLUSIONS: RCM and dermoscopy provide significant clinical value in vitiligo staging. RCM shows higher positive percent agreement for detecting progressive disease, whereas dermoscopy shows higher negative percent agreement for confirming stable disease. These tools offer an objective foundation for assessment and support clinical decision-making.