Abstract
Background: No universal consensus about optimal modality for treating the recalcitrant multiple common warts (RMCW). Objective: To evaluate the immunological mechanisms and clinical therapeutic effect of using of intralesional purified protein derivative (PPD) in the treatment of RMCW. Methods: The study included 40 patients with RMCW. They were randomly assigned to 2 groups: first group (20 patients) received intralesional PPD antigen, and second group (20 patients) received intralesional saline as a control group. In both groups, injections were made into single lesions, or largest wart in case of multiple lesions, at weekly intervals, until complete clearance or for a maximum of six treatments. Blood serum was taken at pre-study and at week 6 to measure IL-12 level. Results: A significant difference was found between the therapeutic responses of RMCW to PPD antigen and saline control group (p < 0.001). In the PPD group, complete response was achieved in 75% after 5.8 ± 0.7 sessions' patients presenting with RMCW. There was a statistically significant increase in IL-12 of PPD group versus saline group. No recurrence was observed in the PPD group. Conclusion: Intralesional immunotherapy by PPD antigen is an effective and a safe treatment for RMCW in previously immunized patients.