We studied the efficacy, and time to clearance, of more frequent cryot
herapy of viral warts, by randomizing 225 patients to receive treatmen
t at 1-, 2- or 3-weekly intervals, The mean times to clearance of wart
s in each group were 5.5, 9.5 and 15 weeks in the weekly, 2-weekly and
3-weekly groups, respectively (P < 0.01). Cure rates after 3 months c
orrelated with frequency of treatment (P < 0.05). After 3 months, 43%
(66% of non-defaulters) had cleared in the group treated weekly, 37% (
47%) of the group treated every 2 weeks, and 26% (30%) of those treate
d every 3 weeks. The mean numbers of treatments needed to achieve clea
rance were similar in each group (5.5, 4.75 and 5 treatments). After 1
2 treatments, cure rates were similar for all three groups: 43% for th
e weekly-treated group (3 months), 48% for the 2-weekly group (6 month
s), and 44% for the 3-weekly group (9 months). Percentage cure is rela
ted to the number of treatments received, and independent of the inter
val between treatments, A more rapid cure may, therefore, be achieved
by more frequent treatment.