Post-marketing Surveillance for Microwave Treatment of Plantar and Common Warts in Adults

A handheld microwave device (Swift®, Emblation Limited) has been licenced and available for clinical use since 2016 in the fields of podiatry and dermatology and has been extensively used in treating cutaneous warts. As part of post marketing surveillance by the manufacturer, an online 79-item survey was distributed to podiatry clinics in the United Kingdom with a Swift® device. A total of 126 clinics responded (59.6%). 6998 adults (<65 years) underwent wart treatment with microwave (81.9% plantar warts; 18.1% common, non-plantar warts). The median efficacy rate was reported as 79.2% (65.9 - 87.5%) and 82.3% (71.4 - 100%) respectively. In older adults (over 65 years) efficacy rates were similar for both sites: plantar (73.2%, 50-90%, n=1232) and non-plantar (80.0%, 42.1-100%, n=276). A median of three treatments was required to bring about resolution. Sub-group analysis of the data revealed good clearance rates in patients with diabetes (79.6%), but less in immunocompromised individuals (61.3%) and those with autoimmune disease (58.6%). Overall, mean user satisfaction was rated as “very satisfied” on a 10-point scale (n=93 practices). A small number of adverse events were reported including blistering, superficial ulceration and poor healing were reported (n=7). Despite the limitations of a post-marketing questionnaire survey, these data provide good evidence of the safety and efficacy for Swift® microwave treatment of cutaneous warts.