Progression of skin-limited pediatric-onset discoid lupus erythematosus to diagnosis of systemic lupus erythematosus: results of a multicenter, retrospective cohort study.

Abstract

Pediatric skin-limited discoid lupus erythematosus (DLE-only) is rare, with limited data on risk factors for progression to systemic lupus erythematosus (SLE). To assess incidence, risk factors, and phenotype of pediatric DLE-only progression to SLE. In this 17-site retrospective cohort of pediatric DLE, the primary outcome was time to SLE diagnosis (ACR classification criterion ≥4). Kaplan-Meier estimates for 1-, 2-, and 5-year progression to SLE were generated. Cox proportional hazards modeling identified baseline predictors of progression to SLE. The 1-year progression rate from DLE-only to SLE was 14.4% (95% CI: 9.6-18.9%). Progression to SLE was most strongly associated with baseline ANA positivity (HR 3.71) and older age (HR 1.11/yr). Antiphospholipid antibodies and cytopenias also predicted progression to SLE in multivariable analysis. The SLE phenotype was relatively mild, with most patients developing mucocutaneous and laboratory criteria (22/236, 9%) and few developing other end-organ disease (7/236, 3%). Retrospective design, missing data. ANA-positive DLE-only patients warrant close monitoring for progression SLE, especially within the first year. Severe end-organ disease in DLE patients who progress to SLE is uncommon. Future studies should test whether early recognition and intervention in DLE-only slows progression to SLE.