THE TREATMENT OF PLANTAR WARTS

Topical treatments for cutaneous warts

BACKGROUND

Viral warts are a common skin condition, which can range in severity from a minor nuisance that resolve spontaneously to a troublesome, chronic condition. Many different topical treatments are available.

OBJECTIVES

To evaluate the efficacy of local treatments for cutaneous non-genital warts in healthy, immunocompetent adults and children.

SEARCH METHODS

We updated our searches of the following databases to May 2011: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 2005), EMBASE (from 2010), AMED (from 1985), LILACS (from 1982), and CINAHL (from 1981). We searched reference lists of articles and online trials registries for ongoing trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of topical treatments for cutaneous non-genital warts.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials and extracted data; a third author resolved any disagreements.

MAIN RESULTS

We included 85 trials involving a total of 8815 randomised participants (26 new studies were included in this update). There was a wide range of different treatments and a variety of trial designs. Many of the studies were judged to be at high risk of bias in one or more areas of trial design.Trials of salicylic acid (SA) versus placebo showed that the former significantly increased the chance of clearance of warts at all sites (RR (risk ratio) 1.56, 95% CI (confidence interval) 1.20 to 2.03). Subgroup analysis for different sites, hands (RR 2.67, 95% CI 1.43 to 5.01) and feet (RR 1.29, 95% CI 1.07 to 1.55), suggested it might be more effective for hands than feet.A meta-analysis of cryotherapy versus placebo for warts at all sites favoured neither intervention nor control (RR 1.45, 95% CI 0.65 to 3.23). Subgroup analysis for different sites, hands (RR 2.63, 95% CI 0.43 to 15.94) and feet (RR 0.90, 95% CI 0.26 to 3.07), again suggested better outcomes for hands than feet. One trial showed cryotherapy to be better than both placebo and SA, but only for hand warts.There was no significant difference in cure rates between cryotherapy at 2-, 3-, and 4-weekly intervals.Aggressive cryotherapy appeared more effective than gentle cryotherapy (RR 1.90, 95% CI 1.15 to 3.15), but with increased adverse effects.Meta-analysis did not demonstrate a significant difference in effectiveness between cryotherapy and SA at all sites (RR 1.23, 95% CI 0.88 to 1.71) or in subgroup analyses for hands and feet.Two trials with 328 participants showed that SA and cryotherapy combined appeared more effective than SA alone (RR 1.24, 95% CI 1.07 to 1.43).The benefit of intralesional bleomycin remains uncertain as the evidence was inconsistent. The most informative trial with 31 participants showed no significant difference in cure rate between bleomycin and saline injections (RR 1.28, 95% CI 0.92 to 1.78).Dinitrochlorobenzene was more than twice as effective as placebo in 2 trials with 80 participants (RR 2.12, 95% CI 1.38 to 3.26).Two trials of clear duct tape with 193 participants demonstrated no advantage over placebo (RR 1.43, 95% CI 0.51 to 4.05).We could not combine data from trials of the following treatments: intralesional 5-fluorouracil, topical zinc, silver nitrate (which demonstrated possible beneficial effects), topical 5-fluorouracil, pulsed dye laser, photodynamic therapy, 80% phenol, 5% imiquimod cream, intralesional antigen, and topical alpha-lactalbumin-oleic acid (which showed no advantage over placebo).We did not identify any RCTs that evaluated surgery (curettage, excision), formaldehyde, podophyllotoxin, cantharidin, diphencyprone, or squaric acid dibutylester.

AUTHORS' CONCLUSIONS

Data from two new trials comparing SA and cryotherapy have allowed a better appraisal of their effectiveness. The evidence remains more consistent for SA, but only shows a modest therapeutic effect. Overall, trials comparing cryotherapy with placebo showed no significant difference in effectiveness, but the same was also true for trials comparing cryotherapy with SA. Only one trial showed cryotherapy to be better than both SA and placebo, and this was only for hand warts. Adverse effects, such as pain, blistering, and scarring, were not consistently reported but are probably more common with cryotherapy.None of the other reviewed treatments appeared safer or more effective than SA and cryotherapy. Two trials of clear duct tape demonstrated no advantage over placebo. Dinitrochlorobenzene (and possibly other similar contact sensitisers) may be useful for the treatment of refractory warts.

Topical treatments for cutaneous warts

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.

Local treatments for cutaneous warts

BACKGROUND

Viral warts caused by the human papilloma virus represent one of the most common diseases of the skin. Any area of skin can be affected although the hands and feet are by far the commonest sites. A very wide range of local treatments are available.

OBJECTIVES

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

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register (January 2003), the Skin Group trials register (January 2003), MEDLINE (1966 to January 2003), EMBASE (1980 to January 2003) and a number of other key biomedical and health economics databases. In addition the cited references of all trials identified and key review articles were searched. Pharmaceutical companies involved in local treatments for warts and experts in the field were contacted. The most recent searches were carried

SELECTION CRITERIA

Randomised controlled trials of local treatments for cutaneous non-genital viral warts in immunocompetent human hosts were included.

DATA COLLECTION AND ANALYSIS

Study selection and assessment of methodological quality were carried out by two independent reviewers.

MAIN RESULTS

Fifty two trials were identified which fulfilled the criteria for inclusion in the review. The evidence provided by these studies was generally weak because of poor methodology and reporting. In 17 trials with placebo groups that used participants as the unit of analysis the average cure rate of placebo preparations was 30% (range 0 to 73%) after an average period of 10 weeks (range 4 to 24 weeks). The best available evidence was for simple topical treatments containing salicylic acid, which are clearly better than placebo. Data pooled from six placebo-controlled trials show a cure rate of 144/191 (75%) compared with 89/185 (48%) in controls, odds ratio 3.91 (95% confidence interval 2.40 to 6.36), random effects model. Most of the bigger trials of cryotherapy studied different regimens rather than comparing cryotherapy with other treatments or placebo. Pooled data from two small trials that included cryotherapy and placebo or no treatment, showed no significant difference in cure rates. In two trials comparing cryotherapy with salicylic acid and one comparing duct tape with cryotherapy no significant difference in efficacy was demonstrated. There was no consistent evidence for the effectiveness of intralesional bleomycin. Four studies, using warts rather than individuals as the unit of analysis, had widely varying results which could not be meaningfully pooled. There was some evidence for the efficacy of dinitrochlorobenzene, a potent contact sensitizer. Pooled data from two small studies comparing dinitrochlorobenzene with placebo showed cure rates of 32/40 (80%) and 15/40 (38%) respectively, odds ratio 6.67 (95% confidence interval 2.44 to 18.23), random effects model. Only limited evidence was found for the efficacy of topical 5-fluorouracil, intralesional interferons and photodynamic therapy.Bleomycin, dinitrochlorobenzene, 5-fluorouracil, interferons and photodynamic therapy are potentially hazardous or toxic treatments.

REVIEWER'S CONCLUSIONS

There is a considerable lack of evidence on which to base the rational use of the local 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 and some evidence that it is only of equivalent efficacy to simpler, safer treatments. Dinitrochlorobenzene appears to be effective but there were no statistically significant differences when compared with the safer, simpler and cheaper topical treatments containing salicylic acid. The benefits and risks of 5-fluorouracil, bleomycin, interferons and photodynamic therapy remain to be determined.

Guidelines for the management of cutaneous warts

These guidelines for the management of cutaneous warts have been prepared for dermatologists on behalf of the British Association of Dermatologists. They present evidence-based guidance for treatment, with identification of the strength of evidence available at the time of preparation of the guidelines, and a brief overview of epidemiological aspects, diagnosis and investigation.