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

• Published in: Journal of the American Academy of Dermatology 2007-12, Vol.57 (6), p.1019-1020
• Main Authors: Burkhart, Craig G., MD, MPH, Pchalek, Irene, BIS, Adler, Melissa, Burkhart, Craig N., MD, MSBS
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Cryosurgery - methods; Dermatology; Freezing; Human viral diseases; Infectious diseases; Medical sciences; Nitrogen - therapeutic use; Nonprescription Drugs - therapeutic use; Temperature; Viral diseases; Viral diseases with cutaneous or mucosal lesions and viral diseases of the eye; Warts - surgery
• ISSN: 0190-9622; 1097-6787
• DOI: 10.1016/j.jaad.2007.06.037

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