Background/Purpose: Pediatric localized scleroderma (LS) is an autoimmune skin and soft tissue disease that causes morbidity via progressive skin fibrosis and extracutaneous manifestations (ECMs), such as arthritis or uveitis.  Studies in other pediatric rheumatic disease populations have shown racial/ethnic differences in outcomes, but such differences have not received significant attention in LS.  We examined racial/ethnic differences in the LS cohort enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) registry.

Methods: Participants with a sole diagnosis of LS (i.e. no other rheumatic diseases) and complete data for gender and race/ethnicity were included for analysis.  Participants who were both white (race) and non-Hispanic (ethnicity) were included in the non-Hispanic white (NHW) group.  All other participants (i.e. nonwhite race, multiracial, and/or Hispanic ethnicity) were in the racial/ethnic minority (REM) group.

Depending on the variable type and distribution, t-test or Wilcoxon rank sum test and Chi-square or Fisher exact test were used to assess differences in outcomes and baseline visit variables between NHW and REM group. 

Results: A total of 369 participants were included, with 301 (82%) in the NHW group and 68  (18%) in the REM group.  Most participants were white (n = 333; 90%) and 42 (11%) were Hispanic.  The majority of participants were female (n = 279; 76%).  Median age at onset was 7.7 years old (IQR: 4.5-11.2) and at first rheumatologist visit was 10.0 years old (IQR: 6.8-12.9).  The study sample was representative of the major LS subtypes, with linear trunk/limb subtype most common (n = 126; 34.1%).  The REM group showed trends toward lower rates of linear trunk/limb subtype (23.5% vs. 36.5%; p = 0.057) and higher rates of linear face/scalp subtype (26.5% vs. 16.9%; p = 0.099). REM participants were significantly more likely to report under $50,000 in annual household income (45.8% vs. 28.2%; p = 0.025).

Participants in the REM group were significantly more likely to have active disease (i.e. PGA > 0 in 80% vs. 58%; p = 0.002).  Median PGA was also significantly higher in the REM group than in the NHW group (2 [IQR: 1-3] vs. 1 [IQR: 0-3]; p = 0.015).  No differences were noted for patient-reported outcomes (pain scale, global well-being scale, quality of life, Childhood Health Assessment Questionnaire).  No differences were noted in other potential confounders of PGA, including: age at onset and first rheumatologist visit; time from onset to first rheumatology visit; lesion location; ECMs; laboratory tests (i.e. ANA, creatine kinase, aldolase); present/past systemic immunosuppressive treatment; or hemifacial atrophy.   

Conclusion: REM group LS patients enrolled in this large, multicenter cohort were more likely than NHW to have active disease.  Differences in rates of disease subtypes (linear trunk/limb vs. face/scalp) and socioeconomic status (e.g. annual household income) were also noted and their possible contribution to the relationship of race/ethnicity and disease activity warrants further investigation.  Future studies should collect detailed sociodemographic data, examining both clinical and social determinants of outcomes in LS.

« Back to 2015 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/relationship-of-race-ethnicity-and-outcomes-in-pediatric-localized-scleroderma-possible-differences-in-disease-activity/