Racial Disparities in the Incidence of Primary Chronic Cutaneous Lupus Erythematosus in the Southeastern US: The Georgia Lupus Registry

• Type of Material: Article
• Authors: Cristina Drenkard, Emory University; Sareeta Parker, Emory University; Laura Aspey, Emory University; Caroline Gordon, University of Birmingham; Charles G. Helmick, Centers for Disease Control and Prevention; Gaobin Bao, Emory University; Sung Lim, Emory University
• Language: English
• Date: 2019-01-01
• Publisher: Wiley Inc.
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2018, American College of Rheumatology
• Final Published Version (URL): http://dx.doi.org/10.1002/acr.23578
• Title of Journal or Parent Work: Arthritis Care and Research
• Volume: 71
• Issue: 1
• Start Page: 95
• End Page: 103
• Grant/Funding Information: Financial Support: This research was supported by the CDC, and by cooperative agreement CDC-RFA-DP08-806 and earlier by cooperative agreement PA03022 from the CDC. C.D. and S.S.L. are supported by the NIH (R01AR065493-01; R01MD010455-01; R01AR070898-01) and the CDC (U01DP005119).
• Keywords: FRENCH-GUIANA; Life Sciences & Biomedicine; POPULATION; Rheumatology; PREVALENCE; QUALITY; LIFE; EPIDEMIOLOGY; MANIFESTATIONS; Science & Technology; SPECTRUM
• Research Categories: Health Sciences, Public Health; Health Sciences, Medicine and Surgery

Abstract

Objective: Relative to studies of systemic lupus erythematosus (SLE), epidemiologic studies of chronic cutaneous lupus erythematosus (CCLE) are rare and are limited to populations with no racial diversity. We sought to provide minimum estimates of the incidence of primary CCLE (CCLE in the absence of SLE) in a population comprised predominantly of white individuals and black individuals in the southeastern region of the US. Methods: The Georgia Lupus Registry allowed for the use of multiple sources for case-finding, including dermatology and rheumatology practices, multispecialty health care facilities, and dermatopathology reports. Cases with a clinical or clinical/histologic diagnosis of CCLE were classified as definite. Cases ascertained exclusively from dermatopathology reports were categorized as probable. Age-standardized incidence rates stratified by sex and race were calculated for discoid lupus erythematosus (DLE) in particular and for CCLE in general. Results: The overall age-adjusted estimates for combined (definite and probable) CCLE were 3.9 per 100,000 person-years (95% confidence interval [95% CI] 3.4–4.5). The overall age-adjusted incidences of definite and combined DLE were 2.9 (95% CI 2.4–3.4) and 3.7 (95% CI 3.2–4.3) per 100,000 person-years, respectively. When capture–recapture methods were used, the age-adjusted incidence of definite DLE increased to 4.0 (95% CI 3.2–4.3). The black:white and female:male incidence ratios for definite DLE were 5.4 and 3.1, respectively. Conclusion: Our findings underscore the striking racial disparities in susceptibility to primary CCLE, with black individuals having a 3-fold to 5-fold increased incidence of CCLE in general, and DLE in particular, compared with white individuals. The observed sex differences were consistent with those reported previously, with a 3 times higher risk of DLE in women compared with men.