Laser treatment of onychomycosis due to Neoscytalidium dimidiatum: An open prospective study

Abstract

Conventional systemic and topical treatments have proven ineffective for the treatment of onychomycosis caused by Neoscytalidium dimidiatum. Our aim was to evaluate the effectiveness and safety of laser monotherapy for the treatment of onychomycosis caused by this pathogen. Patients with clinical onychomycosis of the toenails and positive results both on direct mycological examination and N. dimidiatum culture underwent four 1064 nm Nd:YAG laser sessions with 6-week intervals between sessions. Participants were monitored by clinical examination supported by dermoscopy, measurement of diseased nail and the onychomycosis severity index (OSI), and by mycological examination for 12 months after completion of treatment. Treatment outcome was based on clinical and laboratory criteria and was divided in complete or partial cure, clinical improvement, treatment failure and relapse. No patient had complete or partial cure at any time during the study. Clinical improvement was observed in 40.6% of the patients at the end of the laser sessions; however, it did not persist during the follow-up. Treatment failure was observed in 64.7% of the patients at the end of 12 month follow-up period. Direct microscopy and culture results remained positive in most patients. Adverse events, in addition to treatment-related pain, were observed and considered severe in one case. The 1064 nm Nd:YAG laser was not able to cure onychomycosis caused by N. dimidiatum but temporarily improved the clinical appearance of the nail; however, adverse events may occur.

Identification and biofilm development by a new fungal keratitis aetiologic agent

“…In general, human infections by Neoscytalidium could be disseminated, subcutaneous and cutaneous, with the latter occurring more frequently in tropical and subtropical countries. These infections are clinically indistinguishable from dermatophyte infections . Typically, these fungi infect nails and skin and the infections are difficult to treat .…”

“…However, Neoscytalidium dimidiatum, while not a frequent human pathogen, is able to generate phaeohyphomycosis, which may be manifested as disseminated infections or as subcutaneous and cutaneous infections (cerebral and pulmonary infections, atrial fungal endocarditis, mycetoma, onicomicosis). In some cases, these infections have been fatal . Neoscytalidium keratitis is rare although some instances of the infection have been documented…”

Complete cure of Fusarium solani sp. complex onychomycosis with Qs NdYAG treatment

“…There are no previous reports of successful treatment of NDM OM with any laser or light system, to the best of our knowledge. In a recent report of 36 patients with Neoscytalidium dimidiatum OM, treated with four 6 weekly sessions of 1,064 nm Nd:YAG laser, clinical improvement occurred in only 40%, at the end of laser treatment, but did not persist and most patients remained culture positive at 12 months (Leverone, Guimarães, Bernardes‐Engemann, & Orofino‐Costa, ). No laser/light based treatment has previously been tried for Fusarium OM.…”

“…With respect to the available evidence, although abundant literature is available, only a few well designed studies have been done so far. Long-pulsed Nd:YAG has been used with widely variable results (cure rate of 9.3% by Moon, Hur, Oh, and Choi [2014] vs over 90% by Kozarev [2011]). Short pulsed Nd-YAG systems have also shown conflicting results in in vitro and in vivo studies (Choi, Zheng, Goo, & Cho, 2014;Gupta & Paquet, 2015).…”