Influence of smoking on the efficacy of antimalarials in cutaneous lupus: a meta-analysis of the literature.

BACKGROUND: Interaction between smoking and efficacy of antimalarials, the mainstay of treatment for cutaneous lupus erythematosus (CLE), remains controversial.

OBJECTIVES: We systematically reviewed the evidence for such an interaction and performed a meta-analysis to compare the efficacy of antimalarials among smoker versus nonsmoker patients with CLE.

METHODS: Observational studies published up to March 2014 in the MEDLINE, Embase, and Cochrane databases were selected if they reported on the efficacy of antimalarials for treatment of CLE, according to smoking status. The strength of association between smoking and cutaneous response rate was expressed using the odds ratio. Individual study odds ratios were combined in the meta-analysis using a random effects model.

RESULTS: Of 240 citations retrieved, 10 studies met inclusion criteria, for a total of 1398 patients. The pooled odds ratio for the response to antimalarials in smoker patients with CLE (n = 797) was 0.53 (95% confidence interval 0.29-0.98) compared with nonsmokers (n = 601).

LIMITATIONS: Subgroup analyses for the response to antimalarials considering CLE subtypes, type, and dosage of antimalarials could not be performed because of the lack of available data.

CONCLUSIONS: Smoking is associated with a 2-fold decrease in the proportion of patients with CLE achieving cutaneous improvement with antimalarials. Smoking cessation should be considered in patients with CLE and refractory cutaneous involvement.