Cantharidin (1%), podophyllin (5%), and salicylic acid (30%) formulation in recalcitrant plantar warts: Analysis of 48 patients

A plantar wart is a benign hyperplasia that appears on the feet due to the human papillomavirus (HPV). One method used for the treatment of recalcitrant plantar warts, those lasting over 2 years or persisting after at least two treatment attempts, is the cantharidin (1%), podophyllin (5%), and salicylic acid (30%) formulation, also known as the CPS formulation. Although this method is in use, there are few studies on it. This study's objective was to ascertain its cure rate. For this retrospective observational study, we reviewed the medical records of patients treated with the CPS formulation at a podiatric clinic specializing in plantar wart treatment. Our sample size was 48 subjects. The CPS formulation had a cure rate of 62.5%. Out of the cured patients, 86.67% (26/30) required one or two applications. There was no observable correlation (p > 0.05) between wart resolution and virus biotype, evolution time, patient's morphological and clinical attributes, location, number of warts, or preceding treatments. The CPS formulation presents a relatively high efficacy rate for treating recalcitrant HPV plantar warts. Still, additional studies are necessary to evaluate its safety and efficiency.