Continuous terbinafine and pulse itraconazole for the treatment of non-dermatophyte mold toenail onychomycosis

Prognostic factors for mycological cure in patients with onychomycosis caused by Neoscytalidium dimidiatum: A retrospective cohort study

BACKGROUND

The prognostic factors for cure have been derived from cases of dermatophyte onychomycosis. However, there are limited studies in non-dermatophyte onychomycosis. Neoscytalidium dimidiatum is the common causative agents of non-dermatophyte onychomycosis which has proven to be recalcitrant to treatment.

OBJECTIVE

This retrospective cohort study investigated mycological cure and prognostic factors in Neoscytalidium onychomycosis patients.

METHODS

Patients aged 18 or older with newly diagnosed Neoscytalidium onychomycosis were enrolled. All patients were treated and followed up for at least 1 year. Mycological cure was analysed with Cox proportional hazard regression. The hazard ratios (HRs) of previously reported potential prognostic factors were included in univariable and multivariable stratified Cox regression analyses.

RESULTS

From total 198 patients, mycological cure was achieved in 108 (54.6%) patients with a median of 490 (± SD 62.2) days. The poor prognostic factors for mycological cure were age ≥ 70 years (HR, 0.63; 95% CI, 0.41-0.97; p = .034); nail thickness ≥2 mm (HR, 0.20; 95% CI, 0.11-0.35; p < .001); and peripheral vascular disease (HR, 0.46; 95% CI, 0.28-0.77; p = .003). Combination therapy was associated with achieving a mycological cure (HR, 2.55; 95% CI, 1.49-4.38; p < .001).

CONCLUSIONS

Approximately half of the patients with onychomycosis caused by Neoscytalidium dimidiatum achieved a mycological cure, with a median time to cure exceeding 1 year. Combined topical and systemic antifungal treatments yield a higher chance of mycological cure than monotherapies. Advanced age, nail thickness and peripheral vascular disease are obstacle factors to cure.

Onychomycosis in Older Adults: Prevalence, Diagnosis, and Management

The risk of having onychomycosis increases with age. Data suggest that the prevalence of onychomycosis may be ≥ 20% in subjects aged ≥ 60 years and ≥ 50% in those aged ≥ 70 years. Older males are 2.1 times more prone to onychomycosis than are females. Although most nail dystrophies (approximately 50%) are caused by onychomycosis, proper clinical assessment followed by mycological examination is recommended to exclude other conditions such as nail trauma, lichen planus, and psoriasis. The US FDA-approved onychomycosis treatments are systemic antifungals (terbinafine and itraconazole) for severe onychomycosis and topical antifungals (ciclopirox 8%, efinaconazole 10%, and tavaborole 5%) for mild-to-moderate onychomycosis. Oral fluconazole is used off-label, and itraconazole may be considered for non-dermatophyte onychomycosis. Recently, fosravuconazole was approved in Japan for onychomycosis treatment. Although the treatment options and durations are the same for older patients as for other age groups, a clinical decision should take into account various age-related factors such as comorbidities, polypharmacy, hepatic and renal insufficiency, and noncompliance. Clinicians should also consider possible drug interactions and side effects when choosing a particular antifungal. Since the recurrence rate of onychomycosis is high, older patients should practice sanitization techniques, consider lifestyle changes, and perhaps consider using a topical antifungal as long-term maintenance therapy one to three times per week to prevent the recurrence of onychomycosis or to treat early disease.

Molecular characterization and antifungal activity against non-dermatophyte molds causing onychomycosis

Onychomycosis is a fungal disease that caused by different types of fungi. Non-dermatophyte molds are a large saprophytic fungi group that live in nature and could affect traumatic nails. The aim of this study was to identify non-dermatophyte molds causing onychomycosis and evaluation of several antifungal activities against the isolates. The samples consisted of 50 non-dermatophyte molds isolated from patients with onychomycosis confirmed by direct and culture examination fungal. DNA was extracted, amplified, and sequenced. Disk diffusion method was used to evaluate itraconazole, fluconazole, ketoconazole, terbinafine, posaconazole, and econazole activity against the isolates. The species identified as: Aspergillus flavus 22 (44%), A. niger 12 (24%), A. fumigates, 3 (6%), A. sydowii 3 (6%), A. terreus 1 (2%), Penicillium commune 2 (4%), P. glabrum 2 (4%), P. chrysogenum, 1 (2%), Fusarium solani 3 (6%) and F. thapsinum 1 (2%). Most of the samples were sensitive to terbinafine, itraconazole, and econazole and 94% of the isolates were resistant to fluconazole. This study showed that Aspergillus species were the most common cause of non-dermatophyte mold onychomycosis and fluconazole was the most resistant antifungals. Care must be taken to choose the appropriate antifungal drug for a better cure.

Nondermatophyte mould onychomycosis

Nondermatophyte moulds (NDMs) onychomycosis is often difficult to diagnose as NDMs have been considered contaminants of nails. There are several diagnostic methods used to identify NDMs, however, repeated laboratory isolation is recommended to validate pathogenicity. With NDM and mixed infection (dermatophytes plus NDM) onychomycosis on the rise, accurate clinical diagnosis along with mycological tests is recommended. Systemic antifungal agents such as itraconazole and terbinafine (e.g. pulse regimen: 1 pulse = every day for one week, followed by no treatment for three weeks) have shown efficacy in treating onychomycosis caused by various NDMs such as Aspergillus spp., Fusarium spp., Scopulariopsis brevicaulis, and Onychocola canadensis. Studies investigating topical therapy and devices for NDM onychomycosis are limited. The emergence of antifungal resistance necessitates the incorporation of antifungal susceptibility testing into diagnosis when possible, for the management of recalcitrant infections. Case studies documented in the literature show newer azoles such as posaconazole and voriconazole as sometimes effective in treating resistant NDM onychomycosis. Treatment with broad-spectrum antifungal agents (e.g. itraconazole and efinaconazole) and other combination therapy (oral + oral and/or oral + topical) may be considerations in the management of NDM onychomycosis.

Methylene blue vs methyl aminolevulinate photodynamic therapy in the treatment of mild-to-moderate toenail onychomycosis: Short- and medium-term effects

Photodynamic therapy (PDT) has emerged as an interesting alternative option for onychomycosis treatment. The impact of a specific photosensitizer (PS) on the final result is an important factor to consider. We conducted a short- and medium-term controlled trial to compare the effectiveness of PDT in the treatment of mild-to-moderate onychomycosis when it is mediated by two different PSs. Twenty patients were randomized to receive nine sessions of PDT distributed over 16 weeks mediated either by methylene blue (MB/PDT group) or methyl aminolevulinate (MAL/PDT group). Onychomycosis severity index (OSI) and nail involvement were checked along the study. Complete cure, treatment success, and clinical improvement were tabulated at 16 and 40-week follow-ups. OSI scores decreased significantly along the study, from 12.1 ± 5.4 to 3.6 ± 3.2 (MB/PDT group) and from 14.8 ± 6.0 to 5.4 ± 4.4 (MAL/PDT group). At 16-week follow-up, only 20% of the patients in the MB/PDT group reached complete cure and none in the group of MAL/PDT. At 40-week follow-up, complete cure rates were 70% and 40% in the MB/PDT group and MAL/PDT group respectively. Both modalities showed good outcomes in treatment of moderate toenail onychomycosis. MB/PDT showed a faster action but with relapse rates slightly higher than MAL/PDT.