Efficacy and safety of single versus multiple intralesional immunotherapy with purified protein derivative (PPD) in the treatment of multiple verruca vulgaris.

Multiple injections of warts with PPD cleared more patients with multiple common warts than the use of single injections at the end of 12 weeks and were faster in clearing patients at every time point. Single injection was better tolerated than multiple injections. Both treatments exhibited similar safety profiles and recurrence rates.