Study of the Ideal Method in Cryotherapy of Wart

Background: Cryotherapy of warts with liquid nitrogen is the most widely used method of treatment by dermatologist, but little is known about its ideal method. Objective: This study is to investigate the ideal methods in cryotherapy of warts. Methods: 127 cases of viral warts were studied. These warts consisted of three groups of verruca vulgaris, palmoplantar wart, and periungual wart. 104 cases were treated with a Cry-Ac® spray, 23 cases with a cotton wool bud. Using either technique, liquid nitrogen was applied until ice-ball formation had spread from the center to include a margin of 2-4 mm around each wart. Treatment was done at 2-week or 3-weekly intervals and with two to six freeze thaw cycles. The endpoint of the study was complete clearance of all warts. Result: Each cure rate for treatment interval is 70.0% for 2-weekly treatment, and 71.6% for 3-weekly treatment. The rate of pain and blister with a shorter interval is higher. Each cure rate for freeze thaw cycles is 73.7% for 2 cycles, 70.4% for over 3 cycles. The morbidity for blister is higher in over 3 cycles than 2 cycles. Cure rates were 70.2% in the spray and 73.9% in the cotton wool bud. Conclusion: This study shows no significant benefit of the trial beyond 2 freeze-thaw cycles. We suggest that 3-weekly treatment is the optimal treatment and cryotherapy is equally effective when treated with a spray or a cotton wool bud.