I do not know of anyone who is thrilled when they see a recalcitrant or extensive case of cutaneous warts. The treatments we currently have simply do not work that well. While data report that salicylic acid (SA) and cryodestruction have wart cure rates of 52% and 49%, respectively,1 these rates are misleading because the growths can go away on their own. Although data is limited, a recent study showed two-thirds of warts go through spontaneous regression within a 2-year period.2 However, many persist longer and are refractory despite a number of tools for treatment. A Cochrane meta-analysis found that SA and cryotherapy were marginally effective at best.3 All other treatments, from intralesional bleomycin to duct tape, were either ineffective or marginally effective or had insufficient high-quality studies to make a determination.3 Further, little data exists to support surgical removal as a treatment option. Experience and anecdotal evidence show that surgical removal is effective, but the majority of patients are not prime candidates and would likely prefer a nonsurgical or topical approach that is fast and effective.
The only FDA-approved topical medication currently to treat cutaneous warts is 17% SA, which must be applied for months for a chance to get a modest effect. If surgical removal of the wart is not possible, more data-driven professionals may have a detailed conversation with a patient discussing the self-limited nature of warts and the limitations of nonsurgical treatment. But most of the time, health care professionals initiate cryotherapy and hope for the best.
Attempts have been made to improve the effectiveness of topical treatment. Compounding pharmacies routinely make SA plasters, and some clinicians advise SA along with imiquimod or 5-fluorouracil (5-FU) under tape occlusion. Verrumal, a combination of 0.5% 5-FU and 10% SA, has been available for the last 30 years in Europe. This combination of 5-FU and SA has been found to be superior to 5-FU alone for the treatment of common and plantar warts.4 Across all studies, complete healing was achieved in 63.4% of common warts treated with 5-FU/SA compared with only 23.1% treated with 5-FU alone. Similar disparity in complete healing was seen in plantar warts (63% vs 11%, respectively). However, these cure rates4 were achieved over a 1 to 3 months and not a few weeks as patients desire.
As we well know in dermatology, even the best topical medication is useless unless it can penetrate the skin and reach its desired target, hopefully without adversely affecting normal tissue. In a rapidly growing, hyperkeratotic cutaneous wart, this is a significant challenge. Occlusion can increase the potency of topicals, but if they migrate off the skin (as they inevitably do in the standard solution, gel or cream), they can then cause excessive irritation, which often leads to treatment failure. Furthermore, pulse dosing to allow the irritation to subside does not work well for warts due to their rapid regrowth rate.
Dermatology, perhaps more than any other specialty, knows the benefits that compounded medications can provide for individualizing treatments, and creating novel formulas to solve tough problems.
Wartpeel (WP), a 5-FU (2%) and SA (17%) compounded medication, was patented in 2010. Its development began in 1991 as a collaboration between a pharmacist and a podiatrist to treat plantar warts. The treatment uses a sustained-release topical adhesive gel that releases SA onto the wart to break down keratinocytes and subsequently allow better penetration of 5-FU to the living wart.5
At the time I discovered this product, I was working in a low-income area with a high pediatric population and saw between three to five patients with warts per day, much of which recalcitrant. With the exception of surgical removal, all other treatments my colleagues and I tried (cryotherapy, Candida antigen, cantharidin, among others) were only marginally effective; so, I began to experiment with WP. After treating hundreds of patients, I have observed a cure rate of 95% in 1 to 2 weeks (unpublished data), which far exceeds in any nonsurgical method in speed and effectiveness. Additionally, the recurrence rate is low and patient satisfaction is high due to excellent tolerability, even in children, and the fast treatment time. For all these reasons, WP has become a valuable first-line therapy and, in many cases, indispensable.
The information and photos contained in this article (and subsequent articles in this series) will accelerate your mastery of WP and allow you to manage even the most extensive and recalcitrant cutaneous wart cases. This article will highlight the properties of WP, show how it worked in a severe, recalcitrant case of periungual warts, and discuss key patient education points.