An open, comparative clinical study on the efficacy and safety of 10% trichloroacetic acid, 25% trichloroacetic acid and cryotherapy for verruca plana

OBJECTIVE: Although there are several methods to treat Verruca plana, warts do not respond well to the common therapeutic options. In this study, we compared the safety and efficacy of 10% trichloroacetic acid, 25% trichloroacetic acid, and cryotherapy for the treatment of warts caused by Verruca plana. METHODS: Ten percent and 25% trichloroacetic acid were applied to warts weekly until all lesions cleared. Cryotherapy was performed by liquid nitrogen spray for 5-10 seconds for each lesion per week until the lesions cleared. The number of Verruca plana lesions and adverse effects were evaluated five times during the treatment (the initial visit, week 2, week 4, week 6, and week 8). RESULTS: The number of lesions decreased through week 8 for all three treatments, and the reductions in the mean numbers of lesions were statistically similar (p > 0.05). Those in the cryotherapy group exhibited more erythema, pain, erosions, bullae, and hyperpigmentation (p < 0.001, p < 0.001, p < 0.001, p < 0.05, and p = 0.001, respectively) than those in either TCA group. Itching was more common among those in the trichloroacetic acid groups than in the cryotherapy group (p < 0.05). Additionally, hyperpigmentation, erythema, pain, and itching were more frequent in the 25% trichloroacetic acid group than in the 10% trichloroacetic acid group (p < 0.001), (p < 0.05), (p < 0.05), (p < 0.05). CONCLUSION: Ten percent trichloroacetic acid, 25% trichloroacetic acid, and cryotherapy are effective methods to treat Verruca plana. 10% trichloroacetic acid offers a safer and easier treatment than either 25% trichloroacetic acid or cryotherapy.