Efficacy of Intralesional Purified Protein Derivative (PPD) in Refractory Warts: A Randomized Placebo-Controlled Study

INTRODUCTION: This study aimed to evaluate the efficacy and safety of intralesional Purified Protein Derivative (PPD) in patients with recalcitrant warts in a randomized, double-blind, placebo-controlled setting.
METHODS: A total of 55 patients with treatment-resistant warts were enrolled between July 2003 and February 2005. Participants were randomized into two groups: one received intralesional PPD injections, and the other received placebo (saline) at two-week intervals for a total of four sessions. Only one target lesion per patient was injected. Baseline and post-treatment wart dimensions were recorded, and patients were followed for two months after treatment completion. Clinical response was categorized as complete, partial, minimal, stable, or progressive. Adverse effects were monitored throughout the study.
RESULTS: Forty-five patients completed the treatment and follow-up period. Both groups showed statistically significant reductions in target wart size (PPD: from 34.86 ± 30.58 mm² to 13.55 ± 21.71 mm², p<0.001; Placebo: from 48.65 ± 62.08 mm² to 23.96 ± 21.45 mm², p<0.05). Complete or ≥50% regression was observed in 68.2% of the PPD group and 50.8% of the placebo group; however, the difference between groups was not statistically significant (p>0.05). No serious adverse effects were reported, and minor local reactions occurred in only two patients in the PPD group.
DISCUSSION AND CONCLUSION: Intralesional PPD is a safe and potentially effective therapeutic option for recalcitrant warts. Although clinical improvements were observed, its efficacy did not significantly differ from placebo in this trial.

Keywords: Human papillomavirus, Immunotherapy, Intralesional PPD, Randomized controlled trial, Recalcitrant warts.