Duct tape may not be superior to placebo in the treatment of common warts
Article Outline
- de Haen M, Spigt MG, van Uden CJT, van Neer P, Feron FJM, Knottnerus A. 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
- References
- Copyright
de Haen M, Spigt MG, van Uden CJT, van Neer P, Feron FJM, Knottnerus A. 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
Question Among children with verruca vulgaris infection, is duct tape more likely than placebo to eradicate the wart?
Design Randomized placebo-controlled trial.
Setting Three primary schools in Maastricht, the Netherlands.
Participants 103 children 4 to 12 years of age with verruca vulgaris.
Intervention Duct tape applied to the wart or placebo (a corn pad [protection ring for clavi]), applied around the wart for 1 night a week. Both treatments were applied for a period of 6 weeks. Patients were blinded to the hypothesis of the study.
Outcomes Complete resolution of the treated wart.
Results After 6 weeks, the wart had disappeared in 16% of the children in the duct tape group compared with 6% in the placebo group (P = .12). The estimated effect of duct tape compared with placebo on diameter reduction of the treated wart was 1.0 mm (P = .02, 95% confidence interval, −1.7 to −0.1). After 6 weeks, in seven children (21%) in the duct tape group, a surrounding wart had disappeared compared with nine children (27%) in the placebo group (P = .79). Fifteen percent of the children in the duct tape group reported adverse effects such as erythema, eczema, and wounds compared with 0 in the placebo group (P = .14).
Conclusions In a 6-week trial, duct tape had a modest, but nonsignificant, effect on wart resolution and diameter reduction when compared with placebo in a cohort of primary school children.
Comment Warts are common problem in primary care, and a quick, well proven, inexpensive treatment is not available. An earlier randomized, controlled trial compared duct tape with cryotherapy, showing duct tape to be beneficial.1 In contrast, the present study reports no significant difference in complete resolution of warts between the two groups. Coupled with complications of duct tape (15% developed skin reactions), the authors concluded that duct tape was ineffective in treating warts. Several limitations in the study lead us to question this conclusion. First, considering epidemiological data showing that 30% of warts resolve without treatment by 32 weeks,2 the mean length of time that subjects had had their warts was quite long—34.2 weeks for the experimental group and 38.5 weeks for the control group. Also, many subjects had already tried another treatment. Therefore, subjects’ warts may be particularly resistant not only to spontaneous resolution but also to any treatment, and the subjects may not be representative of those who would likely consider the treatment in question. Second, the analysis included all subjects, even those who did not complete treatment. This intention-to-treat analysis was designed to produce conclusions that are more applicable to real-life situations. However, including in the analysis those who did not finish the treatment could dilute a positive effect. Third, the investigators had determined that a 30% effect size would be clinically meaningful, and they adjusted the sample size accordingly. Yet, some clinicians and wart-sufferers may feel that an even smaller effect size is clinically meaningful, given the feasibility of duct tape therapy. Thus, when 16% of the warts in the treatment group resolved, compared with 6% in the placebo group, the study was not powered to detect this smaller difference. Finally, subjects were followed for 6 weeks, which may have been too short a time to see the full effect of duct tape. At 6 weeks, the mean decrease in diameter of the treatment group warts was greater than that of the placebo group. If subjects had been followed for longer, a greater difference between the two groups might have been detected. Although the authors suggest that duct tape therapy is ineffective, further studies that address the above limitations are needed before such definitive conclusions can be drawn.
References
PII: S0022-3476(07)00190-4
doi:10.1016/j.jpeds.2007.02.051
© 2007 Mosby, Inc. All rights reserved.
