Case Rep Dermatol 2018;10:216–225 DOI: 10.1159/000492526 Published online: August 31, 2018 © 2018 The Author(s) Published by S. Karger AG, Basel www.karger.com/cde This article is licensed under the Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC) (http://www.karger.com/Services/OpenAccessLicense). Usage and distribution for commercial purposes requires written permission. Rachel Bertolani do Espírito Santo Rua Nancy Alves Vieira de Menezes, nº50, aptº1.203 Bairro Mata da Praia, Vitória, Espírito Santo 29.065-560 (Brazil) E-Mail rabertolani@gmail.com Case Series Case Study of Onychomycosis Patients Treated with 1,064-nm Nd:YAG Laser Rachel Bertolani do Espírito Santo Patrícia Duarte Deps Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, Brazil Keywords Onychomycosis · 1,064-nm Nd:YAG laser · Onychomycosis Severity Index Abstract Onychomycosis is the most frequent nail disease, with an estimated prevalence of 2–8%. Cur- rent treatment strategies include the use of oral and topical antifungals, despite low cure rates following these treatments. The objectives of this study were to assess the therapeutic re- sponse of patients with onychomycosis to 1,064-nm Nd:YAG laser treatment, the clinical eval- uation method available for this therapy, and the possible side effects of this treatment. Twenty patients with onychomycosis underwent laser therapy. A total of 34 nails with onychomycosis were assessed according to the Onychomycosis Severity Index (OSI). This index generates scores that classify onychomycosis as mild, moderate, or severe. The OSI was determined be- fore treatment and after a mean follow-up period of 8 months. The comparison between the initial and the final OSI for all 34 nails treated with laser therapy showed a significant difference; however, a low association was shown between these variables. A general reduction in the area of involvement and in the OSI numerical scores was observed. These data show a trend toward improvement in onychomycosis treated with 1,064-nm Nd:YAG laser. The OSI allowed an ad- equate clinical assessment of the response to laser therapy. Laser treatment did not cause marked discomfort in most patients, indicating that laser is a well-tolerated procedure. © 2018 The Author(s) Published by S. Karger AG, Basel