Cryotherapy of viral warts

A total of 144 patients with at least one viral hand wart were treated with liquid nitrogen cryotherapy in an open, multicentre, prospective study. The aim of the study was to determine the optimum interval between cryotherapy treatments. An effort was also made to determine whether the cure rate was related to the age of the patient, the duration of the disease and/or the total number of warts. The patients were grouped according to age, duration of disease and number of warts, and an index finger wart not previously treated with cryotherapy was the basis for randomization of the patients for treatment at 2-, 3- or 4-week intervals until cure was achieved or a maximum of six treatments had been given. Cure rates were evaluated 3 and 6 months after the initiation of treatment. The cure rates of the index wart were 71% and 65% evaluated after 3 and 6 months, respectively. After 6 months, cure rates of 63%, 70% and 63% were seen for index warts treated with cryotherapy at 2-, 3- and 4-week intervals, respectively. If the index wart was not cured after four or five freezings, further cryotherapy was unlikely to be successful. For the wart disease of the patients in general, the cure rates were 22% and 29% after 3 and 6 months. The best cure rates were found among young patients with few warts of short duration.