Laser therapy for onychomycosis in patients with diabetes at risk for foot ulcers: a randomized, quadruple-blind, sham-controlled trial (LASER-1)

[[[ Background: ]]] Patients with diabetes mellitus are at high risk for onychomycosis, which is related to the development of foot ulcers. [[[ Objective: ]]] The aim of this study was to evaluate the safety and efficacy of the treatment of onychomycosis with local laser therapy. [[[ Methods: ]]] In a single-centre, randomized (1:1), quadruple-blind, sham-controlled trial, patients and microbiological confirmation with diabetes mellitus, at risk for developing diabetic foot ulcers (Sims classification score 1, 2) and a clinical suspicion on onychomycosis, were randomized to either four sessions neodymium-doped yttrium aluminium garnet (Nd-YAG) 1064 nm laser or sham treatment. The primary outcome was clinical and microbiological cure of onychomycosis after 1-year follow-up. [[[ Results: ]]] From March 2015 to July 2016, 64 patients were randomized; 63 could be analysed. Trichophyton rubrum was the most detected pathogen. There was no difference in the primary outcome between laser and sham treatment. With the exception of a subungual haematoma in the fifth toenail occurring 2 weeks after laser treatment, the results suggested that treatment with Nd-YAG 1064 nm laser is safe. [[[ Conclusion: ]]] At this moment, there is no evidence of any effect of laser treatment for onychomycosis in patients with diabetes at increased risk for foot ulcers, at least not within 1 year after treatment.