An in vitro study comparing temperatures of over-the-counter wart preparations with liquid nitrogen.

Abstract

Over-the-counter (OTC) wart-freezing therapies have appeared on the market claiming that they reproduce in-office cryotherapy. We sought to determine whether these OTC home wart removal products are as cold as liquid nitrogen. The coldness obtained by 3 representative commercial wart products, and liquid nitrogen, was assessed using a thermometer calibrated from -100 degrees C to 50 degrees C. Temperatures of the commercial wart products used were measured and compared with those obtained with liquid nitrogen. None of the OTC coolants were as cold as liquid nitrogen, and they did not lower temperature as quickly as liquid nitrogen. This study did not evaluate the clinical efficacy of any of the agents studied. Despite advertising messages, OTC refrigerants do not achieve freezing equivalent to liquid nitrogen.