Coexistence of systemic and localized scleroderma: a systematic literature review and observational cohort study

Objective. SSc and localized sclerosis (LoS) are considered clinically distinct entities. We describe herein the coexistence of SSc and LoS by both a systematic literature review and an observational cohort study of unselected SSc patients. Methods. Original studies documenting the coexistence of SSc and LoS were identified in three electronic databases by means of a systematic literature search according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Additionally, the coexistence of SSc and LoS was studied in a prospective cohort of SSc patients visiting the Ghent University Scleroderma Unit for their yearly follow-up visit between January 2018 and January 2019. Results. Five studies were finally included for quality appraisal and data extraction. The coexistence of SSc and LoS ranged between 2.4 and 7.4%. RP, scleroderma pattern on nailfold videocapillaroscopy (NVC) and the presence of SSc-specific antibodies were commonly observed in coexistent cases. Additionally, coexistence of SSc and LoS was found in 8/296 (2.7%) consecutive SSc patients of the Ghent University Scleroderma Unit. RP was present in 6/8 coexistent cases; a scleroderma pattern on NVC was observed in all coexistent cases, and SSc-specific antibodies (i.e. cenp-B) were found in 4/8 coexistent cases. Conclusion. This is the first systematic literature review with additional cohort evaluation investigating the coexistence of SSc and LoS. A relatively high overlap of SSc and LoS was revealed, which is peculiar because both are rare diseases.