Potassium Hydroxide Solution for the Treatment of Cutaneous and Anogenital Warts: A Narrative Review

Background: Multiple options exist for the treatment of viral warts, but there is not yet a treatment capable of inducing a complete sustained response in all cases. The aim of this narrative review was to evaluate the efficacy and safety of KOH solution in cutaneous and anogenital warts. Methods: A literature search was conducted using the PubMed, Ovid Medline, Google Scholar, Scopus and Embase electronic databases and focusing on articles published in English that described the effects of monotherapy with KOH solution on different wart types. Results: We selected 24 studies involving 2083 patients, of whom 1423 were recruited in KOH groups. The heterogeneity in study designs, patient populations, outcomes and intervention characteristics (e.g., concentration of KOH, frequency of application, and treatment duration) precluded the possibilities of performing a meta-analysis and making direct comparisons among the studies. In many studies, there were small patient samples and short follow-up periods. However, despite such limitations, the available results regarding the use of KOH solution for warts seem to show efficacy rates comparable to those of established therapies, including TCA solution and cryotherapy. Side effects were generally described as mild and transient. KOH-related adverse events include burning sensation, erythema, dyspigmentation, and superficial erosions. Conclusions: Preliminary data suggest the potential clinical utility of KOH solution for the treatment of warts, although more data are needed to obtain definite conclusions and to optimize treatment protocols. Further research should include high-quality studies with extended follow-up periods and standardized outcome measures.