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Three Part Question

In [children with verrucas] does [treatment with duct tape]bring about [resolution of verrucas]?

Clinical Scenario

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.

Search Strategy

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.

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.
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.

Search Outcome

3 relevant papers

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Focht et al, 2002	51 children and young people aged 3–22 years with verrucas, recruited from clinic 26 treated with duct tape (for a maximum of 2 months) 25 received cryotherapy (maximum of 6 treatments 2–3 weekly)	Prospective RCT (level 1b)	Complete resolution at 2 months	Complete resolution: Tape – 22/26 (85%) Cryotherapy – 15/25 (60%) Statistically significant (p=0.05)	61 patients initially enrolled, 10 lost to follow-up (4 in duct tape arm, 6 in cryotherapy arm)
			Time to complete resolution	Resolution at 28 days: Tape – 16/22 (73%) Cryotherapy – 9/15 (60%)
de Haen et al, 2006	103 children aged 4–12 years with verrucas, recruited from primary schools 51 treated with duct tape (for 6 weeks) 52 given placebo, a corn pad (for 6 weeks)	Prospective RCT (level 1b)	Complete resolution at 6 weeks	Complete resolution: Tape – 8/51 (16%) Placebo – 3/52 (6%) Not statistically significant NNT 10 (95% CI 5 to ∞)	Side effects in duct tape arm: skin irritation, 15% reported erythema Difficulties securing tape, 81% reported that the duct tape would not stick
			Reduction in diameter at 6 weeks	Reduction in diameter: Tape – 27%, to 3.4 mm Placebo – 9%, to 4.0 mm (p=0.02)
Wenner et al, 2007	80 adults with verrucas, recruited from clinic 39 treated with duct tape (for 2 months) 41 given placebo (moleskin) (for 2 months)	Prospective RCT (level 1b)	Reduction in diameter at 2 months	Reduction in diameter: No statistically significant differences in decrease in diameter/height between treatment groups (p>0.11)	10 lost to follow up. 5 in duct tape arm; 3 due to side effects. 5 in placebo arm; 1 due to side effects Side effects in duct tape arm: reported by 1 participant who finished the study (tingling when bandaged too tight), however, 3 left the study due to side effects
			Recurrence 6 months after end of treatment	Recurrence Tape – 6/8 Placebo – 3/9 Not statistically significant (p=0.15)

Comment(s)

Verrucas are common. Prevalence varies with age, with the lowest estimates at 4% and the highest at 24% (Gibbs). Those at highest risk are young people sharing communal ‘bare-foot’ areas (Gibbs). Current first line therapies for verrucas are ‘wart paints’ usually containing salicylic acid, or cryotherapy (Gibbs). 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 (Focht, de Haen, Wenner). 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 the table.

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 (de Haen). 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 (Wenner). We also noted one participant undertaking duct tape treatment lost their verruca due to a trampoline accident in which their toe was amputated (Focht). 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 (see ADC http://adc.bmj.com/content/96/9/897.full). 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 months (Focht) and reduction in diameter (de Haen), 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.

Editor Comment

NNT, number needed to treat; RCT, randomised controlled trial.

Clinical Bottom Line

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)

References

1. Gibbs S, Harvey I, Sterling JC, et al . Local treatments for cutaneous warts. Cochrane Database Syst Rev 2003;3:CD001781.
2. Focht DR 3 rd., Spicer C, Fairchok MP . The efficacy of duct tape vs cryotherapy in the treatment of verruca vulgaris (the common wart). Arch Pediatr Adolesc Med 2002;156:971–4.
3. de Haen M, Spigt MG, van Uden CJT, et al . Efficacy of duct tape vs placebo in the treatment of verruca vulgaris (warts) in primary school children. Arch Pediatr Adolesc Med 2006;160:1121–5.
4. Wenner R, Askari SK, Cham PMH, et al . Duct tape for the treatment of common warts in adults: a double-blind randomized controlled trial. Arch Dermatol 2007;143:309–13.