An estimated 30% of the adult population in developed countries are smokers, and smoking is the leading preventable cause of illness and death in the Western world. The results of epidemiological studies suggest that smoking may influence the development and progression of various skin diseases, including cutaneous lupus erythematosus (CLE).1 Here we discuss the results of 2 recently published studies in which the influence of smoking on cutaneous manifestations of lupus erythematosus was investigated.

Kuhn et al.2 conducted a cross-sectional multicenter study of 1002 patients from 14 European countries. They found that the data on smoking obtained by questionnaire by the European Society of Cutaneous Lupus Erythematosus (EUSCLE) correlated with the severity of CLE (Cutaneous Lupus Erythematosus Disease Area and Severity Index [CLASI]) and with the response to treatment with antimalarials. The authors found that the prevalence of smoking among patients with CLE (59.5%) was significantly higher than the estimated prevalence among the adult population in Europe (25%-30%). Moreover, 87.2% of smokers with CLE reported having started smoking before the appearance of disease symptoms, supporting the hypothesis that smoking may contribute to the induction of CLE. The CLASI score was also significantly higher in patients that smoked, indicating that smoking may exacerbate the cutaneous manifestations of the disease. Another important clinical finding was that the response rate to treatment with chloroquine/hydroxychloroquine was significantly lower in patients that smoked.

Bourre-Tessier and coworkers3 conducted a prospective multicenter study of 1346 patients from 14 centers in Canada to evaluate the influence of smoking on cutaneous manifestations in patients with systemic lupus erythematosus. Multivariate analysis revealed a significant association between active smoking and the presence of malar rash. However, the authors found no clear association between past tobacco use and the presence of active cutaneous manifestations. Moreover, they found no association between smoking and the presence of mucosal lesions in patients with systemic lupus erythematosus.

In conclusion, increasingly strong scientific evidence suggests a negative effect of smoking in CLE patients, in terms of both the severity of manifestations and the response to treatment. The fact that a clear association with cutaneous manifestations is observed in active smokers but not ex-smokers supports the view that patients with lupus should be advised to quit smoking.