Cochrane Review: Topical treatments for cutaneous warts
Authors: Gibbs Sam , Harvey Ian 
Published: September 2011

Background

Viral warts are common and usually harmless but very troublesome. A very wide range of local treatments are used.

Objectives

To assess the effects of different local treatments for cutaneous, non‐genital warts in healthy people.

Search strategy

We searched the Cochrane Skin Group Specialised Register (March 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2005), MEDLINE (1966 to March 2005), EMBASE (1980 to March 2005) and a number of other biomedical databases. The references of all trials and selected review articles were also searched. In addition, we contacted pharmaceutical companies involved in local treatments for warts and experts in the field

Selection criteria

Randomised controlled trials of local treatments for cutaneous non‐genital viral warts in immunocompetent (healthy) people.

Data collection and analysis

Data was extracted and two authors independently selected the trials and assessed methodological quality.

Main results

Sixty trials were identified that fulfilled the criteria for inclusion. The evidence provided by these studies was generally weak due to poor methodology and reporting.

In 21 trials with placebo groups that used participants as the unit of analysis, the average cure rate of placebo preparations was 27% (range 0 to 73%) after an average period of 15 weeks (range 4 to 24 weeks).

The best available evidence was for simple topical treatments containing salicylic acid, which were clearly better than placebo. Data pooled from five placebo‐controlled trials showed a cure rate of 117/160 (73%) compared with 78/162 (48%) in controls, which translates to a risk ratio of 1.60 (95% confidence interval 1.16 to 2.23), using a random effects model.

Evidence for the absolute efficacy of cryotherapy was surprisingly lacking. Two trials comparing cryotherapy with salicylic acid and one comparing duct tape with cryotherapy showed no significant difference in efficacy.

Evidence for the efficacy of the remaining treatments reviewed was limited.

Authors' conclusions

There is a considerable lack of evidence on which to base the rational use of topical treatments for common warts. The reviewed trials are highly variable in method and quality. Cure rates with placebo preparations are variable but nevertheless considerable. There is certainly evidence that simple topical treatments containing salicylic acid have a therapeutic effect. There is less evidence for the efficacy of cryotherapy, but reasonable evidence that it is only of equivalent efficacy to simpler and safer treatments. The benefits and risks of topical dinitrochlorobenzene and 5‐fluorouracil, intralesional bleomycin and interferons, photodynamic therapy and other miscellaneous treatments remain to be determined.

Plain Language Summary

Topical treatments for skin warts

Viral warts are one of the most common skin diseases. They are caused by the human papilloma virus and most commonly found on the hands and feet. While warts are not harmful and usually go away in time without any treatment, they are unattractive and can be painful. Warts can be removed with wart paints containing salicylic acid. These are cheap and readily available, but slow to work. Cryotherapy, usually using liquid nitrogen, is often considered more effective than wart paints but is more expensive. The review of trials found that there was not enough evidence to compare treatments and that there was not enough evidence to support the use of cryotherapy (freezing) over wart paints as initial treatment for viral warts. More research is needed.