Report of an association between discoid lupus erythematosus and smoking.

Smoking has been shown to be associated with many medical disorders, including many involving the skin. While preliminary studies suggest a modest association between smoking and systemic lupus erythematosus, epidemiologic data on discoid lupus erythematosus (DLE) and smoking are lacking. To study this relationship, we examined current smoking habits in two unique patient populations with DLE. One group was compared with matched dermatology patients while the second group was compared with the corresponding statewide population. For both groups, the current smoking prevalence was much higher than that of the comparison population. For the control-matched group of DLE patients, smoking prevalence was found to be significantly greater than that of controls (odds ratio 12.2; p = 0.001). We therefore propose that smoking is a risk factor for development of DLE.