Cantharidin–podophylotoxin–salicylic acid versus cryotherapy in the treatment of plantar warts: a randomized prospective study

BACKGROUND: Plantar warts are refractory to any form of treatment. High cure rates have been reported with a topical proprietary formulation consisting of 1% cantharidin, 5% podophyllotoxin and 30% salicylic acid (CPS). However, no data exists comparing the efficacy of this formulation with another treatment. Cryotherapy is a method that is also widely used in the treatment of plantar warts. Likewise, there is no evidence that it is more effective than any topical treatment. OBJECTIVE: We aim to compare the efficacy of topical CPS and cryotherapy in the treatment of plantar warts. METHODS: Patients with plantar warts were consecutively treated with either cryotherapy or topical CPS. Both treatments were performed every 2 weeks for up to five sessions. In patients without complete clearance, the therapy was switched to the other treatment option. RESULTS: Twenty-six patients with a total of 134 warts were included. Fourteen patients were completely cleared of their warts with topical CPS, whereas only in five of 12 patients (41.7%) warts were completely cleared with cryotherapy (P=0.001). In seven patients without complete clearance, the therapy was switched to CPS. Four of these patients missed the follow-up. While the two of the remaining three patients were cleared of their warts, one patient's warts still failed to clear. CONCLUSION: Topical CPS is more effective than cryotherapy in the treatment of plantar warts.