Duct Tape May Be Comparable to Cryotherapy for Simple Warts
Source: Focht DR III, Spicer C, Fairchok MP. The efficacy of duct tape versus cryotherapy in the treatment of verruca vulgaris (the common wart). Arch Pediatr Adolesc Med. 2002;156: 971–974.[Abstract/Free Full Text]

To compare the efficacy of duct tape and cryotherapy for the treatment of common warts, these investigators enrolled patients aged 3–22 years who presented to the pediatric or adolescent clinics at the Madigan Army Medical Center in Washington State between October 31, 2000 and July 25, 2001. Patients were eligible for inclusion if they had a common wart and did not have an immunodeficiency state; chronic skin disease; allergy to adhesive tape; warts located on the face or periungual, perianal or genital areas; or previous cryotherapy for the same wart. Warts were measured at baseline and at each follow-up visit; those patients who failed to return were contacted by telephone to determine response to treatment. At study entry, patients were randomized to receive either cryotherapy or duct tape application. Those in the cryotherapy group were treated with liquid nitrogen for 10 seconds every 2–3 weeks until the wart resolved or until 6 treatments had been administered. Those in the duct tape group applied the tape to the wart and left it in place for 6 days; thereafter, the tape was removed and the wart debrided with an emery board or pumice stone. The following morning, duct tape was reapplied and the cycle repeated. Patients in this group were re-evaluated monthly and treatment continued until the wart resolved or the wart had been treated for 2 months. The primary outcome measure was the percent of warts that resolved completely after 2 months; a secondary outcome variable was the time to resolution.

Of 61 patients enrolled, 51 completed the study (25 cryotherapy, 26 duct tape); 10 patients (6 cryotherapy, 4 duct tape) were unavailable for follow-up and were excluded. Patients in the final treatment groups did not differ significantly with respect to age, gender, baseline wart size, or wart location (most warts were located on the fingers). Complete wart resolution occurred in 85% of patients in the duct tape group versus 60% treated with cryotherapy (P=.05). The majority of warts that resolved with duct tape therapy did so within 28 days (16 of 22 [73%]); if no response was seen within 2 weeks resolution was unlikely to occur. Of 15 warts that responded to cryotherapy, 9 (60%) resolved after 2 treatments. Thus, the average time to complete resolution was considered similar for both treatments. An unspecified number of patients (more in the duct tape group) had follow-up conducted by telephone. The most frequent complications in the duct tape group were local skin irritation and difficulty keeping the tape in place; for those in the cryotherapy group, pain at the treatment site was the most common adverse reaction.

Commentary by Daniel P. Krowchuk, MD, FAAP
Pediatrics and Dermatology, Wake Forest University School of Medicine, Winston-Salem, NC

 
Warts are a common problem, affecting 10% of the population at some time.1 Although it is impossible to predict the natural history of individual warts, studies conducted among institutionalized children indicate that two-thirds of lesions resolve spontaneously within 2 years.2 A number of therapies exist, but the response to any given modality is variable. A systematic review was recently published.3 Among the most common treatments are the application of a keratolytic agent (eg, those containing salicylic acid) and cryotherapy, each of which has an ultimate cure rate of approximately 75%.1 Anecdotal reports have suggested that the application of adhesive tape may be effective. In the present report, the authors demonstrate that the application of duct tape produces a cure rate of 85% and is more effective than cryotherapy. Their findings may be limited because of the loss of 16% of patients initially enrolled, a factor that could have affected the magnitude of the observed difference in efficacy between the 2 treatment groups.4 In addition, an unspecified number of patients did not return for re-evaluation; as a result, wart size and resolution were assessed by parental report. Also not known was the degree to which subjects adhered to duct tape therapy, or if other treatments were employed during the study. Nevertheless, these findings suggest that application of duct tape may be as effective as many other available modalities. It has the advantages of being painless and inexpensive, and eliminates the need for return visits to providers.

Editors’ Note
Duct tape appears to be the newest—if not the coolest—addition to our armamentarium of therapies for uncomplicated warts. Like many others—including topical salicylic or lactic acid—it seems to work, if...you stick with it. That said, the commentary4 points out that the article reports a P-value but not a confidence interval (CI) which is a more clinically relevant measure. Both the P-value and the CI are based on the outcome and numbers of patients randomly assigned to each group; the P-value is the probability that the findings are due to chance (under the assumption that the treatment isn’t effective); the 95% CI provides a best-case and worst-case measure of treatment effect—there is a 95% chance that the truth lies within this range. The authors calculated that duct tape was 24.6% superior to cryotherapy with a 95% CI of 1% to 48%. So, the bottom line is that while duct tape worked somewhat better than the cryotherapy in this study, it is not certain that it is a lot better. However, it does appear to be equally effective.

References

   1. Krowchuk DP. Warts and molluscum contagiosum. In: Burg FD, Inglefinger JR, Wald ER, Polin RA, eds. Current Pediatric Therapy 16. Philadelphia, PA: WB Saunders; 1999:970–974.
   2. Massing AM. Arch Dermatol. 1963;87:306–310.[Medline]
   3. Gibbs S. BMJ. 2002;325:461–463.[Free Full Text]
   4. Ringold S. Arch Pediatr Adolesc Med. 2002;156:975–977.[Free Full Text]