Sepehr Bazrafkan, Afshan Shirkavand, Elaheh Nahvifard,
Volume 16, Issue 3 (Volume 16, No 3 2025)
Abstract
Cutaneous warts are among the most common benign skin lesions and, due to their high prevalence, risk of infection, and cosmetic concerns, they remain a frequent focus of clinical attention. Among the available treatment modalities, cryotherapy is widely used as a first-line option owing to its simplicity, low cost, and high success rate. However, the optimal choice of probe temperature and freeze duration still largely relies on clinical experience, and uncertainties in tissue thermal parameters may result in incomplete treatment or unintended damage to surrounding healthy tissue.
In this study, a numerical model was developed to investigate the temperature distribution within human skin during the cryotherapy of warts. The model is based on the radial heat-conduction equation and incorporates temperature-dependent thermophysical properties of human skin as reported by Agafonkina et al. (2021). Simulations were performed for a range of probe surface temperatures between -30 °C and -70 °C, and the temporal evolution of the wart center temperature was examined until it reached the cellular destruction threshold. The results indicate that lowering the probe temperature accelerates the freezing process; however, below approximately -55 °C, this enhancement becomes saturated and the risk of collateral tissue damage increases. Based on the obtained optimization map, the optimal probe temperature was found to lie within the interval -45 to -55 °C, for which the wart core reaches the critical temperature (-20°C) within 5 to 8 seconds. Comparison with clinical data demonstrates that the developed numerical model can serve as an effective tool for predicting and optimizing cryotherapy parameters, thereby improving treatment precision and reducing the likelihood of clinical error.
