Juvenile- and adult-onset systemic sclerosis: similarities and differences in early disease patterns: a scoping review.

OBJECTIVES: Juvenile systemic sclerosis (jSSc) is a rare disease associated with high morbidity and a significant mortality risk. Improving recognition of early disease could enable earlier treatment initiation and a reduced risk for irreversible damage such as lung fibrosis. We conducted a scoping review to understand the early jSSc disease pattern and compared it with the early adult SSc pattern. METHODS: A systematic search of PubMed, Embase, MEDLINE, and CENTRAL (January 1946-April 2026) identified studies reporting clinical features of jSSc (≥3 patients) or aSSc (≥500 patients). Included studies were stratified by disease duration into early (≤3 years) and late (≥5 years) strata. Studies requiring fulfilment of the 1980 ACR or 2007 PRES/ACR/EULAR criteria were considered to represent late rather than early disease. RESULTS: Thirty-nine studies (935 jSSc; 15,451 aSSc patients) from 41 countries were included. jSSc demonstrated predominance of diffuse cutaneous disease (~70% vs. ~41% aSSc), higher rates of overlap features including myositis (33% vs. 5%) and arthritis (32.6% vs. 18%), greater early vascular burden with digital ulcers (51% vs. 20%), and notably low rates of scleroderma renal crisis (0% vs. 6%) in early disease. Crude mortality was lower in jSSc (7.7% vs. 20.4%). CONCLUSIONS: Early jSSc disease shares many similarities with, but also several differences from, early aSSc disease. Understanding these early clinical patterns should improve diagnostic accuracy, support earlier treatment initiation, and reduce tissue damage, thereby improving long-term outcomes for these children.