Update on clinimetric assessments in juvenile dermatomyositis: conceptual foundations, current tools, and future directions : (Narrative review describing the development, validation, and application of clinimetric outcome measures in juvenile dermatomyositis).

BACKGROUND: Juvenile dermatomyositis (JDM) is a complex multi-system disease that significantly impacts the health and development of affected children. Accurate and comprehensive measurement of disease activity and outcomes is essential for effective clinical management and research. Traditional unidimensional measures are insufficient for capturing the multifaceted nature of JDM, necessitating the development of specialized clinimetric tools that integrate multiple health domains and perspectives.

MAIN BODY: Over the past decades, significant advances have been made in developing and validating clinimetric assessments for JDM. Core domains such as muscle strength, skin involvement, global disease activity, and patient-reported outcomes are now routinely evaluated using established instruments like the Childhood Myositis Assessment Scale, Manual Muscle Testing, and various skin assessment tools. Composite indices, including the Juvenile Dermatomyositis Activity Index and the ACR/EULAR Total Improvement Score, enhance sensitivity to clinical changes by integrating multidimensional data. Imaging modalities such as magnetic resonance imaging and muscle ultrasound provide objective insights into muscle inflammation and damage, while histopathology scoring offers valuable research and prognostic information. Despite these advances, challenges remain in standardizing assessments, particularly for skin disease and patient-reported symptoms like fatigue and social participation. Emerging digital health technologies and biomarker integration hold promise for improving longitudinal monitoring and precision in disease evaluation. Additionally, the treat-to-target approach in JDM underscores the need for frequent, accurate measurements to guide therapy adjustments. However, practical barriers including resource limitations and tool complexity hinder widespread clinical adoption.

CONCLUSION: Considerable progress has been achieved in the development of clinimetric tools for JDM, enabling more nuanced and patient-centred disease assessment. Future efforts should prioritize the creation of disease-specific patient-reported outcome measures, streamlined and feasible assessment protocols, and the integration of biological markers and digital innovations. These advances will support precision medicine approaches and improve outcomes for children living with JDM.

CLINICAL TRIAL NUMBER: Not applicable.