Outcome measures for cutaneous and musculoskeletal involvement in juvenile systemic sclerosis: a scoping literature review.

OBJECTIVES: Cutaneous and musculoskeletal involvement are major contributors to morbidity and disability in juvenile systemic sclerosis (jSSc). This scoping review aimed to identify outcome measures used to assess these domains in sclerosis (SSc) to support juvenile SSc clinical trials. METHODS: A scoping review was conducted following PRISMA-ScR guidelines. PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched (1994-2026) for longitudinal studies evaluating skin and musculoskeletal outcome measures in SSc. RESULTS: Of 46,002 records identified, 108 studies met the inclusion criteria; 106 (98.1%) included adults only, whereas two studies included only jSSc patients (n=13). Overall, 35 distinct outcome measures were identified, including 23 clinician-reported outcomes (of which 6 were imaging measures), 9 patient-reported outcomes, 2 performance outcomes, and 1 biomarker. Hand involvement was the most frequently evaluated domain (54 studies), followed by overall function (51), mouth (24), joints/bone/tendon (18), muscle (8), and skin (8). Grip strength was the most frequently reported hand outcome measure. The modified Rodnan Skin Score was the only skin clinician-reported outcome evaluated in paediatric studies. Mouth, joint, and muscle involvement were primarily assessed using interincisal distance, joint counts, and the 6-minute walk test, respectively. CONCLUSIONS: Outcome measures for skin and musculoskeletal involvement in SSc are heterogeneous and derived almost exclusively from adult studies. These findings highlight the need for standardised and validated outcome measures for jSSc and support the on-going International Juvenile Systemic Sclerosis Outcome Group initiative to develop a core outcome set.