Objective: Systemic sclerosis (SSc) is a rare connective tissue disease in childhood. We compared the characteristics of adult patients with juvenile-onset SSc (jSSc) from a single-center cohort to an adult-onset group.
Methods: Patients with disease onset before the age of 17 years were included in the jSSc cohort, while subjects with SSc onset after age 17 formed the adult-onset cohort.
Results: We identified 52 adult subjects with jSSc and compared them to 954 patients with adult-onset SSc. The mean ± SD age at disease onset of the patients with jSSc was 14 ± 2 years, 39 (75%) of them were women, and 24 (46%) had the diffuse cutaneous subset of SSc (dcSSc). There were no differences between the 2 cohorts in terms of sex and disease subset. Overlaps were significantly more frequent among the jSSc cohort (37%) compared to the adult-onset group (18%; p = 0.002). Autoantibody analysis demonstrated significantly more antitopoisomerase I antibody-positive subjects (33% vs 20%; p = 0.034) and significantly fewer anticentromere antibody-positive subjects (2% vs 25%; p < 0.001) in the jSSc cohort. Compared to the adult-onset group at 10 years from disease onset, survival was significantly higher among the subjects with jSSc (98% vs 75%; p = 0.001), pulmonary arterial hypertension had a significantly lower incidence (2% vs 14%; p = 0.032), and there was no difference in terms of pulmonary fibrosis (22% vs 21%) and cardiac scleroderma (3% vs 2%) between the 2 groups.
Conclusion: The high survival rates and lower proportion of dcSSc in the adult jSSc cohort may represent a survival bias.