Document resource
Introduction Localized scleroderma (LS) and systemic sclerosis (SSc) are rare pediatric conditions with distinct clinical profiles but shared fibrosing mechanisms. LS mainly affects skin and subcutaneous tissues, while SSc involves skin and internal organs and carries greater morbidity and mortality. Differences between juvenile- and adult-onset forms have been described, but a systematic effort to capture the specific features of LS and SSc in children is still lacking. This systematic review aimed to describe clinical characteristics, treatment strategies, and survival outcomes in pediatric LS and SSc based on published original studies.Material and Methods The protocol was registered in PROSPERO and conducted according to PRISMA guidelines. Articles were retrieved from PubMed, Cochrane Library, and Web of Science. Two reviewers independently screened abstracts; conflicts were resolved by a third. 10% of data extraction was performed independently by both reviewers to ensure reliability. Data were harmonized to avoid duplicate cohorts. The NOS scale was used for quality assessment.Results Seventy-nine studies including 4178 patients were analyzed: 39 on LS, 19 on SSc, and 3 on both. Most were retrospective, single-center cohort studies; only one randomized trial was retrieved. Median study quality was moderate (NOS score 5.5). LS presented earlier (mean 8.1 years) than SSc (10.1 years), with both showing female predominance (>70%). Linear morphea was the most common LS subtype (58.8%). Extracutaneous manifestations occurred in 37.3% of LS patients, mainly musculoskeletal (29.1%) and neurologic (14%). In SSc, the diffuse cutaneous subtype predominated (70.6%) with frequent Raynaud’s phenomenon (80.4%), interstitial lung disease (39.5%), and gastrointestinal involvement (25.4%). ANA were positive in 25.6% of LS and 86.4% of SSc patients; anti-Scl-70 antibodies were reported in 29.6% of SSc. Methotrexate was the most frequent systemic treatment in both LS (67.9%) and SSc (48%). In SSc, mycophenolate mofetil (38.1%) and cyclophosphamide (14.1%) were also commonly used. Biologics were occasionally reported, including abatacept (9.5%) in LS and rituximab (5.9%) or tocilizumab (12.5%) in SSc. Survival data were limited: mortality was 0.1% in LS and 9% in SSc. Most patients achieved clinical improvement or stability during follow-up.Conclusions This systematic review provides the most comprehensive synthesis to date of juvenile-onset LS and SSc. It highlights distinct phenotypes, frequent extracutaneous involvement, and heterogeneous management, which differ from adult practice. These findings underscore the need for standardized treatment strategies and support the development of prospective studies and dedicated trials in these rare conditions.