A short, 8-week course of imiquimod 5% cream versus podophyllotoxin in the treatment of anogenital warts: A retrospective comparative cohort study.

Background: Studies comparing head-to-head treatment modalities for anogenital warts are lacking.

Aim: We sought to compare a short, 8-week course of imiquimod 5% cream to versus the standard 4 week course of podophyllotoxin in the treatment of anogenital warts and to assess factors that may affect response to treatment.

Methods: This was a retrospective cohort study. We reviewed medical files of otherwise healthy patients with a first episode of anogenital warts who were treated with either a short, 8-week course of imiquimod or the standard 4-week course of podophyllotoxin. Inverse probability of treatment weighted (IPTW). Logistic regression was employed to evaluate factors that may affect response to therapy.

Results: The study included 347 patients. In patients with lesions on dry, keratinized anatomical sites, the complete clearance rates were 7.6% for imiquimod and 27.9% for podophyllotoxin (P < 0.001). In patients with lesions on moist, partially keratinized sites, no difference between the treatments was revealed. Significant predictors of > 50% reduction in wart area were location of lesions [odds ratio (OR) (95% confidence interval (CI)): 3.6 (1.84-7.08), P = 0.0002] for "partially keratinized" versus "keratinized" sites and treatment used [OR (95% CI): 1.79 (1.08-2.97), P = 0.024] for podophyllotoxin versus imiquimod.

Limitations: The retrospective design of the study was a limitation that we mitigated against with the use of IPTW logistic regression.

Conclusion: A standard 4 week course of Podophyllotoxin was more effective than an 8-week course of imiquimod only for lesions on keratinized sites. Treatment with podophyllotoxin and location of lesions on partially keratinized sites were independent predictors of >50% reduction in wart area.