Cigarette Smoking as a Risk Factor for Developing Cutaeous Lupus Erythematosus
Cutaneous lupus erythematosus (LE) encompasses a group of skin disorders that can present with several clinical presentations like chronic cutaneous lupus erythematosus (that includes localized and generalized discoid LE , hypertrophic LE, tumid LE, and lupus panniculitis), subacute cutaneous LE and acute LE. The etiology of LE is presently unknown, but it is thought both genetic and environmental factors play a role in its development. Among environmental factors involved in LE the most well known are sunlight and several drugs. Previous studies have suggested that smoking might be another factor involved in the pathogenesis of LE.
In a recent study published in the September issue of the Archives of Dermatology, a group of dermatologist from 3 different hospitals in France has studied prospectively the relationship of cigarette smoking and alcohol consumption as risk factors for developing cutaneous LE comparing a series of patients with a control group. 108 patients with LE and 216 controls were included in the study. Of the LE patients there were 48.1% of DLE or disseminated DLE, 24.1% of subacute LE, and 15.7% of acute LE, 6.5% of tumid LE, and 5.6% of SLE with no specific cutaneous lesions. 73.1% of the LE patients were smokers while only 49.5% of the controls smoked (P<.001). There was no difference in alcohol consumption between LE patients and controls. Patients who met ACR criteria for SLE smoked less than those who did not, and those with SLE smoked much less (average 5.5 pack-years), than those who did not met ACR criteria for SLE (average 16 pack-years). In addition, patients who had circulating anti-nDNA were less frequently smokers. Globally, patients with LE with only cutaneous involvement, who did not met ACR criteria for SLE, and had no anti-nDNA antibodies were those who smoked most. On the other hand, those patients who ACR criteria for SLE and had anti-nDNA antibodies were those who smoked the least (compared with other LE patients, and even with controls).
These data suggest that cigarette smoking is strongly associated with cutaneous manifestations of lupus erythematosus. The authors hypothesize that smoking can trigger lupus erythematosus through some of its toxic substances (some may also be contained in drugs known to be associated with lupus erythematosus), a possible phototoxic potential, and/or its effects on the immunologic system.
Association of Cigarette Smoking but Not Alcohol Consumption With Cutaneous Lupus Erythematosus
Boeckler P, Cosnes A, Francès C, Hedelin G, Lipsker D.
Arch Dermatol 2009;145(9):1012-1016
Objective: To ascertain whether smoking or alcohol consumption is associated with lupus erythematosus (LE), because this topic is still subject to debate and part of the debate could be related to the fact that smoking and alcohol consumption are specific risk factors for cutaneous LE.
Design: Prospective multicenter case-control study.
Setting: Three French university hospitals.
Patients: One hundred eight patients with LE and 216 control subjects.
Intervention: Standardized questionnaire evaluating cigarette smoking and alcohol consumption.
Main Outcome Measures: The statistical significance of smoking history and alcohol consumption as associated risk factors for LE by estimating matched case-control odds ratios and their 95% confidence intervals, using multiple conditional logistic regression and the Breslow-Day test to investigate differences in quantities of cigarette and alcohol consumption.
Results: Of the LE patients, 73.1% smoked compared with 49.5% of controls, (odds ratio, 2.77; 95% confidence interval, 1.63-4.76). There was no significant difference in alcohol consumption between LE patients and controls. Among the 79 LE patients who smoked, 72 (91.1%) had started smoking before the first manifestation of LE (mean delay between initiation of smoking and first signs of LE, 14.1 years). The LE patients smoked significantly more than controls did (11.7 vs 7.0 packyears; P=.002). The prevalence of smoking among patients who met more than 4 American College of Rheumatology (ACR) criteria and/or with antinuclear DNA antibodies was lower than the prevalence in patients who met fewer than 4 ACR criteria or than the prevalence in controls (P_.001).
Conclusions: Cigarette smoking is associated with LE, but alcohol consumption is not. The risk conferred by cigarette smoking seems highest in patients who meet fewer than 4 ACR criteria and/or who do not have antinuclear DNA antibodies.
