Clinic experience in discoid lupus erythematosus: a retrospective study of 132 cases

Introduction
Lupus erythematosus (LE) is an autoimmune disease characterized by a broad range of cutaneous manifestations. Discoid LE (DLE) is the most common chronic manifestation of LE. Literature reviews show that there are a limited number of large-series studies investigating DLE. Additionally, there is still no consensus on the etiological factors of DLE such as sun exposure and smoking.

Aim
To evaluate the clinical and demographic characteristics of patients with DLE.

Material and Methods
The study included patients who were hospitalized in the inpatient and outpatient clinics at the Dermatology Department. Age, gender, treatment method, history of smoking, antinuclear antibody positivity, progression to systemic lupus erythematosus (SLE), photosensitivity, and laboratory findings were recorded for each patient.

Results
The study included 132 patients comprising 67 (50.8%) men and 65 (49.2%) women. A family history was found in 3.8%, SLE was detected in 5.3%, and photosensitivity was revealed in 50.0% of the patients. ANA positivity was found in 23.7%, a history of smoking was revealed in 61.4%, and chronic sun exposure was detected in 42.4% of the patients.

Conclusions
Discoid LE, though identified long ago, remains unelucidated and there are very few studies in the literature reporting on DLE. The results indicated that smoking and chronic UV exposure are important risk factors for DLE. Moreover, although ANA positivity was high in our patients, the rate of progression to SLE was remarkably low. The results also showed that, contrary to common belief, there is no female preponderance in DLE.