Application of cantharidin-podophyllotoxin-salicylic acid in recalcitrant plantar warts. A preliminary study

Introduction: Plantar warts often are refractory to any treatment and can last for decades in adults. Recalcitrant warts are defined as those that have persisted for more than two years, or after at least two treatment modalities. Methods: A total of 15 consecutive patients with recalcitrant plantar warts were included in this preliminary study. The treatment consisted of applying one to two sessions that comprised compounding 1% cantharidin, 5% of podophyllotoxin, and 30% salicylic acid (CPS), with an interval between applications of four weeks. Results: With treatment and subsequent follow-up for six months, there was complete eradication of lesions in 15 patients, eight (53.3%) required a single application of the solution, and seven (46.7%) two applications, with no side effects. Patient satisfaction related to treatment was measured by a visual analog scale (VAS) of 10 cm in length, with an average score 9.73 +/- 0.46, and all said they would proceed with the treatment again if necessary. Conclusions: Topical treatment by compounding is safe, effective, and a promising therapeutic modality when applied in recalcitrant plantar warts.