Question 3 What is the efficacy of duct tape as a treatment for verruca vulgaris?
- Department of General Paediatrics, Birmingham Children's Hospital NHS Foundation Trust, Birmingham, UK
- Correspondence to Alison Stubbings, Department of General Paediatrics, Birmingham Children's Hospital NHS Foundation Trust, Steelhouse Lane, Birmingham B4 6NH, UK;
- Accepted 5 July 2011
An 8-year-old girl attends a general paediatric outpatient clinic for medical review and it is noted that she has duct tape on her finger. When asked about it, her mother states that duct tape was recommended by a dermatologist for the treatment of verrucas on the girl's fingers and toes. You wonder what the evidence base is for this treatment.
Structured clinical question
In children with verrucas [population] does treatment with duct tape [intervention] bring about resolution of verrucas [outcome]?
Search strategy and outcome
A Cochrane review on the subject of verrucas was published in 2006; this revealed only one relevant paper, which was also identified in the primary search.
We searched the PubMed, Ovid MEDLINE, EMBASE and CINAHL databases, using the search criteria ‘warts’, ‘verrucas’, ‘duct tape’ and ‘children’.
A search of PubMed produced six results, two of which were randomised controlled trials (RCTs) and are included in this review. The other results were comments or letters and are not included. The same search of Ovid MEDLINE, EMBASE and CINAHL produced the same two RCTs.
Due to the paucity of results specific to the paediatric population, we extended our search to include adults, which generated just one further RCT. We also carried out a broader search using Google Scholar with the same search terms, and searched the references in the papers we reviewed, but this did not reveal any further studies.
Verrucas are common. Prevalence varies with age, with the lowest estimates at 4% and the highest at 24%.1 Those at highest risk are young people sharing communal ‘bare-foot’ areas.1 Current first line therapies for verrucas are ‘wart paints’ usually containing salicylic acid, or cryotherapy.1 Duct tape has been proposed as alternative first line treatment.
Treatment of verrucas with duct tape is known as occlusive therapy. This typically involves application of tape for seven continuous days followed by a 12 h overnight rest; this cycle is repeated for a total of 6–8 weeks.2,–,4 This at first seems a bizarre idea and occlusive duct tape therapy has been controversial and has provoked much debate and prompted the conduct of three RCTs during the last 10 years, the results of which are outlined in table 3.
Clinical bottom lines
▶ Verrucas are common in childhood and adolescence.
▶ There is currently insufficient evidence supporting the effectiveness of duct tape to recommend it as routine treatment for verrucas. (Grade D)
The biological plausibility for this treatment is debatable. It is thought that the duct tape acts through stimulation of the patient's immune system by causing local irritation, in a similar manner to the proposed mechanism for cryotherapy. Duct tape certainly seems to cause local irritation in some patients, with around 15% reporting side effects such as erythema.3 It is uncertain from the literature what specifically about duct tape makes it preferable compared with other plaster tapes, but there are no RCTs examining this.
The side effect profile of treatment with duct tape was generally minor, with most people reporting mild skin irritation or erythema. However, in one study three participants left the study due to side effects including discomfort and numbness.4 We also noted one participant undertaking duct tape treatment lost their verruca due to a trampoline accident in which their toe was amputated.2 It is also worth considering the potential embarrassment associated with the overt nature of this treatment.
Having undertaken an extensive search through the medical literature, including nursing databases, published abstracts and posters, we found only the relatively limited literature mentioned above. Due to this, we were especially aware of the possibility of publication bias affecting the results and so have created a funnel plot of these data (figure 1). This shows an even spread, and therefore makes publication bias less likely. There was a small pool of commentary surrounding these studies, but these did not add to the available evidence.
Overall, the pooled results of these studies on clinical resolution are non-significant (RR 1.39, 95% CI 1.00 to 1.91, I2=0%). While the two trials we reviewed suggest statistically significant differences in outcome with the use of duct tape, specifically resolution at 2 months2 and reduction in diameter,3 the clinical significance of the latter results is questionable (a reduction in diameter of 4.0–3.4 mm after 6 weeks of treatment). If occlusive therapy is to be used for the treatment of veruccas, the inconclusive nature of the evidence should be shared with patients and their families.
Bob Phillips, previous verruca sufferer and parent.
“On reviewing this evidence, I have to admit approaching it initially with a great sense of scepticism. As a previous owner of a crop of verrucas, I can confirm the commonality and the irritation. I suffered months of painful applications of salicylate and even the scraping attentions of a local podiatrist. Even after this, I could not conceive of how a bit of tape might be even vaguely helpful.
I was surprised there had been three RCTs: I expected none. I expected marked publication bias: the funnel plot is strikingly symmetrical. I was convinced that when pooling the results, no overall benefit would be found. Yet the result of the pooled analysis is close enough for me to believe that this therapy may well help: after all the CI does only just touch 1.00. There is a 97.5% chance the result may be of some benefit.
Looking at the same evidence, I would suggest an alternative bottom line, based on the probability of success, the low level of rather minor side effects and the practicality of the approach. “Why not try putting a bit of duct tape over the verruca for 6 weeks or so? It seems to work in some people, and if it causes redness or rubbing, then try one of those blaster gels instead.”
The authors would like to thank Dr Bob Phillips for his alternative commentary.
Competing interests None.
Provenance and peer review Not commissioned; internally peer reviewed.