Tratamento da onicomicose causada por Neoscytalidium dimidiatum com laser de neodímio em cristal de ítrio-alumínio-granada (laser Nd:YAG)

Abstract

Conventional topical and systemic treatments have been shown to be ineffective for the treatment of onychomycosis caused by Neoscytalidium dimidiatum. Alternative light-based therapies used for tinea unguium could be effective for other etiologic agents. The objective of this study was to verify the effectiveness, tolerance and safety of the treatment of toenail onychomycosis caused by N. dimidiatum using the neodymium:yttrium-aluminum-garnet (Nd: YAG) as monotherapy. Patients with clinical toenail onychomycosis and direct mycological examination and culture positive for N. dimidiatum were included. The treatment consisted of four Nd: YAG 1064 nm laser sessions with six-week intervals between them. The patients were followed up by clinical evaluation, direct mycological examination and culture for a period of 12 months after the end of the treatment. The outcome criteria of cure was based in clinical features and mycology, and were defined as total cure, partial cure, clinical improvement, therapeutic failure and relapse/reinfection. Total or partial cure were not achieved in this study. There was a temporary clinical improvement in 40% of patients at the end of laser treatment, which did not persist during follow-up. Direct microscopy remained positive in 87.5% patients at the end of treatment and 94.5% at 12 months posttreatment. Neoscytalidium dimidiatum was isolated in culture in 56.2% and 66.7% of the patients at the end of laser treatment and at 12 months follow up, respectively. In addition to pain, adverse events related to the treatment were noted, one of them was considered severe. The Nd: YAG laser was neither effective nor totally safe as monotherapy for onychomycosis caused by N. dimidiatum.