Treatment of verrucae vulgares in general practice — a randomized controlled trial on the effectiveness of liquid nitrogen and the Histofreezer

In general practice, treating verrucae vulgares with liquid nitrogen has some practical drawbacks. Therefore, in a randomized controlled trial this therapy was compared with a new and easy-to-use form of cryotherapy, the Histofreezer. The warts were treated monthly with liquid nitrogen and twice a month with the Histofreezer. Included in the study were 93 patients with 191 verrucae of whom 17 (38 verrucae) did not comply fully during the study. With the liquid nitrogen treatment 66% of warts were cured, and 49% with the Histofreezer treatment (P = 0.08). All verrucae disappeared in 67% of the patients treated with Liquid nitrogen, and in 35% of those treated with the Histofreezer (P = 0.01). For dorsal, non-protuberant and small verrucae, and in patients younger than 21 years, there were almost no differences. In conclusion, the overall results of treatment with liquid nitrogen were better. However, in certain cases, e.g. in young children, the Histofreezer might be attractive. Further study in this direction is recommended.