Cutaneous lupus erythematosus: factors related to cutaneous activity and damage in a cohort of 260 patients from A Coruña, Spain

Abstract

Background Cutaneous lupus erythematosus is a chronic autoimmune disease that can leave important sequelae. Objective To determine the factors that predict the activity and damage of the skin disease, and the impact of tobacco on the efficacy of antimalarials using the Cutaneous Lupus Erythematosus Disease Area and Severity Index. Materials and Methods A consecutive case series was performed on 260 patients with cutaneous lupus erythematosus (α = 0.05; precision ± 6.5%). We carried out a descriptive analysis of the variables included, with a multivariate analysis to measure the association of variables with the Cutaneous Lupus Erythematosus Disease Area and Severity Index activity and damage ( p value < 0.05). Results The Cutaneous Lupus Erythematosus Disease Area and Severity Index activity was greater in smokers than non-smokers (4.0 ±5.3 vs 1.2 ±3.4, p = 0.006). No significant differences were observed in the Cutaneous Lupus Erythematosus Disease Area and Severity Index activity when the efficacy of antimalarials was analyzed between smokers and non-smokers. Cutaneous Lupus Erythematosus Disease Area and Severity Index damage was higher in smokers than in non-smokers (2.0 ± 3.6 vs 1.2 ± 2.6, p = 0.029). Cutaneous Lupus Erythematosus Disease Area and Severity Index activity was associated with: (a) being an active smoker (odds ratio 3.04, 95% confidence interval 1.68–5.51, p < 0.001; regression coefficient 2.05, 95% confidence interval 0.69–3.42, p = 0.003); (b) the chronic cutaneous lupus erythematosus subtype (odds ratio 1.98, 95% confidence interval 1.02–3.84, p = 0.044); and (c) C-reactive protein increase (≥0.5 mg/dL) (regression coefficient 2.56, 95% confidence interval 0.40–4.71, p = 0.020). Cutaneous Lupus Erythematosus Disease Area and Severity Index damage was associated with: (a) the activity (regression coefficient 0.11, 95% confidence interval 0.01–0.20, p = 0.024); (b) the chronic cutaneous lupus erythematosus subtype (regression coefficient 2.46, 95% confidence interval 1.37–3.56, p < 0.001); (c) the use of topical treatment (regression coefficient 1.31, 95% confidence interval 0.01–2.61, p = 0.049); and (d) systemic treatment (regression coefficient 1.44, 95% confidence interval 0.35–2.53, p < 0.010). Conclusion Smoking is related to an increase risk and a greater activity of cutaneous lupus erythematosus. The chronic cutaneous lupus erythematosus subtype and an increased C-reactive protein level were also associated with a higher disease activity. The sequelae were related to the activity, the chronic cutaneous lupus erythematosus subtype, and the use of topical and systemic treatment. The impact of tobacco on the efficacy of antimalarials may be caused by an increase in the severity of the disease more than by resistance in smokers.