Tuesday, September 14, 2010
Freeze Those Warts!
The study, published this month in the Canadian Medical Association Journal by Dutch researchers from Leiden University, attempted to factually establish the efficiency of the most common treatments for warts. The two most common treatments, both offered over the counter, are freezing (liquid nitrogen applied through a special applicator), and the regular application of salicylic acid on the wart. Evidence prior to the study was limited and controversial, slightly favoring salicylic acid. The Dutch researched launched a double blind study for almost 250 patients, with three options: freezing every two weeks, acid daily, and wait-and-see (they sometimes go away on their own). Nurses visited patients after 13 and 26 weeks to measure the efficacy of treatment.
The 13-week results are out, and freezing is winning. The study showed that for all warts, 39% of cryotherapy patients were cured, against 24% for salicylic acid patients, and 16% for do-nothing patients. Common warts (anywhere but on the feet) showed better results, with 49% cure rate for cryotherapy vs. 15% for salicylic acid and 8% for wait-and see. Plantar warts had the worst outlook, and showed no significant differences between approaches, although cure rates were much higher for children (50%) than adolescents (5%). Cure rates were also much lower for patients who had had warts for more than 6 months. The 26-week results confirmed the better efficiency of active vs. passive treatments.
Patients were also much more satisfied with cryotherapy (69% approval) than with salicylic acid (24%) or wait-and-see (22%). Trying to explain the difference between plantar and common warts, the researchers wrote: "These findings suggest that the effect of active treatments on plantar warts is delayed or that more aggressive treatment is needed because of the callosity overlying the warts."
Want to read more about it? Try Medpage, CBC, or Health Day.