Autoimmune Diseases in Patients With Cutaneous Lupus Erythematosus.

Importance: Increased rates of autoimmune conditions have been reported in association with systemic lupus erythematosus (SLE). Little is known about coexisting autoimmune conditions in patients with cutaneous lupus erythematosus (CLE) without SLE. Objective: To determine the prevalence and risk factors of having coexisting autoimmune conditions in patients with CLE. Design, Setting, and Participants: This cross-sectional study was performed from November 2008 to February 2017 at the University of Texas Southwestern Medical Center (UTSW) and Parkland Health and Hospital System, Dallas, Texas. Participants were identified through the UTSW Cutaneous Lupus Registry. All participants had a dermatologist-confirmed diagnosis of CLE using clinicopathological correlation. Exclusion criteria included age younger than 18 years, and meeting at least 4 American College of Rheumatology diagnostic criteria for SLE. Participants with CLE and without concomitant autoimmune diseases were compared by demographic and disease characteristics. Main Outcomes and Measures: The primary and secondary outcomes were presence of coexisting autoimmune condition(s) and individual autoimmune diseases, respectively. Predictor variables significantly associated with coexisting autoimmune diseases were identified by univariate and multivariable logistic regression analyses. Results: Among the 285 participants initially screened, 129 participants with CLE were included (102 [79.1%] female; median age, 49 years [interquartile range, 38.3-57.1 years]). Coexisting autoimmune conditions were found in 23 (17.8%). Autoimmune thyroid disease had the highest frequency at 4.7% (n = 6). Multivariable logistic regression analyses showed that patients with CLE who were white (odds ratio [OR], 2.88; 95% CI, 1.00-8.29; P = .0498), never smokers (OR, 3.28; 95% CI, 1.14-9.39; P = .03), had family history of autoimmune disease (OR, 3.54; 95% CI, 1.21-10.39; P = .02), and history of positive antinuclear antibody test result (OR, 4.87; 95% CI, 1.69-14.03; P = .003) had a significant association with having coexisting autoimmune conditions. Conclusions and Relevance: This study suggests that patients with CLE without concurrent SLE can have increased rates of coexisting autoimmune conditions. Collecting a thorough review of systems can prompt clinicians to pursue further testing and evaluation by other specialists. Future studies investigating development of coexisting autoimmune conditions over time in the CLE population are necessary to confirm these findings.