Epidemiology of cutaneous lupus erythematosus and the associated risk of systemic lupus erythematosus: a nationwide cohort study in Denmark

Abstract

Objectives The objectives of this paper are to describe the epidemiology of cutaneous lupus erythematosus (CLE) and its subtypes in Denmark, and to investigate the probability of receiving a subsequent diagnosis of systemic lupus erythematosus (SLE) and the related time course. Methods A nationwide registry-based cohort study was conducted in Denmark based on data from the Danish National Patient Registry from 1998 to 2013 using International Classification of Diseases, Revision 10. Results We identified 2380 patients with CLE. The annual incidence rate (IR) of CLE was 2.74/100,000 with a female:male ratio of 4:1. During 12,047 person-years of follow-up, 8% were diagnosed with SLE. The probability of receiving a subsequent diagnosis of SLE was 12.9% after 10 years taking death as a competing risk into consideration, and the probability was highest among women and patients diagnosed with subacute CLE. The median time until a diagnosis of SLE was 2.05 years. Conclusions This is the first nationwide study on CLE in Denmark. Although we found the annual IR of CLE and the risk of receiving an additional diagnosis of SLE to be lower than previously described, continued monitoring and thorough information for patients with CLE is important due to the inherent risk of SLE.

Living with Systemic Lupus Erythematosus: A Profile of Young Female Patients

“…Through the identification of the time from the first symptoms to diagnosis, we tried to find out whether the identification of the diagnosis was delayed, with a consequent delay in the initiation of the efficient therapy. Our survey is in agreement with the literature data [16]. The average time of diagnosis in our patients was 1.5 years.…”

“…As many as 83% of patients were diagnosed during the second year of their disease, this indicates that the diagnostics of this disease are good and relatively fast despite the fact that the disease may initially cause significant difficulties with regard to differential diagnostics. The literature states that the average time of diagnosis identification after the first symptoms is 2.06 years [16] which is approximately similar to the data we present.…”

Cutaneous lupus erythematosus and its association with systemic lupus erythematosus: A nationwide population‐based cohort study in Korea

“…Thus, the Korean national database is unique and useful for understanding the natural characteristics of LE in Asians. The annual incidence of CLE in this study (4.36/100 000) was similar to or slightly higher than that in previous reports in Caucasian populations (2.74–4.30/100 000) . In this study, 20.8% of the patients had both CLE and SLE: 4.26% developed SLE after CLE, while 8.52% had SLE first.…”

“…ACLE was not represented in the ICD‐10 codes, possibly because it is considered more a symptom of SLE than that of isolated CLE. Diagnoses of CLE and SLE appearing within 60 days were considered coincident, as the time delay may be due to the gaps between visits to the dermatologists and rheumatologists . To represent the true initial diagnosis of LE in the cohort, we set a burn‐in period of 1 year and patients identified to have had their first diagnosis from 2003 were considered eligible.…”

“…Lupus is known to be 2–3‐times more prevalent among women of color, whereas Caucasians tend to have less severe but longer disease . However, the study populations in previous reports were predominantly white and not racially diverse; thus, the epidemiological information in Asian populations is limited …”