OBJECTIVES: Cutaneous lupus erythematosus (CLE) is a chronic autoimmune disease primarily affecting the skin. Understanding CLE epidemiology is crucial for timely diagnosis and treatment. The objective of this study was to investigate the incidence, prevalence, mortality rates, and risk factors associated with CLE.

METHODS: A systematic search was performed across Embase^® and MEDLINE^® databases (from database inception to May 2023) to identify relevant CLE studies reporting epidemiological data. Two independent reviewers reviewed each study, and a third reviewer resolved disagreements.

RESULTS: The SLR included 28 studies (North America=12; Europe=9; Asia=3; South America=2; Africa, and Oceania=1 each) covering incidence (n=13), prevalence (n=12), mortality rates (n=2), and risk factors (n=5) in CLE patients. The age and gender-adjusted incidence rates for CLE patients ranged from 2.7 cases per 100,000 person-years in Denmark to 4.3 cases per 100,000 person-years in the USA. Further, regarding CLE subtypes, subacute CLE exhibited a lower incidence rate (0.6 to 1.0 per 100,000 person-years) compared to chronic CLE (0.8 to 3.9 per 100,000 person-years). Likewise, the age and gender-adjusted prevalence rate for CLE patients ranged from 30.1 to 108.9 per 100,000 persons, with lower prevalence observed in subacute CLE compared to chronic CLE. Females exhibited higher incidence and prevalence rates than males, while individuals of black ethnicity had higher rates than whites; rates generally increased with age, but no clear trend emerged. The presence of CLE suggested minimal impact on mortality (standardized mortality ratio of 0.6 and 1.2) in two USA-based studies. Further, five studies identified smoking as a risk factor for CLE and its subtypes, particularly discoid lupus erythematosus.

CONCLUSIONS: Global variations in CLE incidence and prevalence are influenced by gender, age, and ethnicity. Studying genetic and environmental factors can reveal underlying causes. Further research is needed on CLE mortality and risk factors.