Efficacy and Safety of Three Cryotherapy Devices for Wart Treatment: A Randomized, Controlled, Investigator-Blinded, Comparative Study

Abstract

IntroductionCutaneous warts are common skin lesions, caused by human papillomavirus. For years, liquid nitrogen is the cryogen of choice for wart treatment. Alternatively, several cryogenic devices for home treatment are commercially available. The present trial assessed efficacy and safety of a novel nitrous oxide-based cryogenic device for home use (EndWarts Freeze® in Europe, Compound W® Nitro-Freeze in the USA).MethodsThis investigator-blinded, controlled, randomized study compared the nitrous oxide device (test product) with a dimethylether propane-based product (Wartner®; comparator 1). Subjects with common or plantar warts (50/50 ratio) were randomized into two groups (n = 58, test product; n = 40, comparator 1). Sequentially, an extra treatment arm (n = 40) was added to compare with a dimethylether-based product with metal nib (Wortie®; comparator 2). Main objective implied comparison of the percentage cured subjects after one to maximum three treatments. Efficacy and safety was evaluated by a blinded investigator.ResultsAfter a maximum of three applications, a significantly (p = 0.001) higher cure rate of 70.7% (Intention-to-Treat analysis) was observed with test product versus 46.2% (comparator 1) and 47.5% (comparator 2). Almost three times more subjects were cured after 1 test product application (29.3%), versus comparator 1 (10.4%) and comparator 2 (12.5%). Reported side effects were transient and typical of cryotherapy. All treatments were well-tolerated.ConclusionThe superior cure rates for the test product versus two comparators can be explained by its design. Combination of nitrous oxide (cooling agent), the specific activation method (holding the liquid coolant in the cap), and skin-conforming polyurethane foam, results in higher cooling efficiency (− 80 °C) and more effective wart freezing. This trial demonstrated that the nitrous oxide device is a safe, user-friendly and effective wart treatment for home use, comparing favourably to dimethylether (propane) devices with higher freezing temperature, regardless of the applicator type.FundingOystershell Laboratories.Trial RegistrationClinicaltrials.gov identifier, NCT03129373.

Superficial cryotherapy using dimethyl ether and propane mixture versus microneedling in the treatment of alopecia areata: A prospective single‐blinded randomized clinical trial

“…The applicator holder with the foam applicator was soaked with DMEP then removed, after waiting for 20 s for the applicator to reach optimum freezing temperature; it was applied over AA skin for 5 s till the appearance of mild frost, then left to thaw for 5 s 16 . The development of erythema over AA patches was considered an endpoint.…”

Efficacy Evaluation of the Pixie® Skin Tag Cryogenic Device on Skin Tags in a Prospective, Single-Blinded, Randomized, Comparative Clinical Trial

“…According to the Risk Management Procedure for the medical device in compliance with ISO 14971, no unacceptable risks were identified. In addition, a previous clinical evaluation of Pixie ® Skin Tag as a treatment of warts only revealed transient, non-serious adverse events (AEs) related to cryotherapy [ 16 ].…”

“…In addition, the device contains a flexible foam nib at the application side that has a flat surface, which allows optimal contact between the cold surface and the often convex, unleveled skin tags. Pixie ® Skin Tag is demonstrated to effectively treat warts by transferring generated cold to the warts and destroying affected tissue [ 16 ].…”

Innovative method to achieve precise cryolysis

“…[Figures 2-4]. [2][3][4] This is particularly useful in pediatric patients who are more apprehensive towards pain and needles. The use of this method also decreases risk of overtreatment and prevents adverse effects.…”