Prognostic factors influencing the treatment outcome of onychomycosis Candida

Epidemiology of Onychomycosis in the United States Characterized Using Molecular Methods, 2015-2024

Onychomycosis is a recalcitrant fungal infection of the nail unit that can lead to secondary infections and foot complications. Accurate pathogen identification by confirmatory testing is recommended to improve treatment outcomes. In this study, we reviewed the records of 710,541 patients whose nail specimens were sent to a single molecular diagnostic laboratory between 2015 and 2024. PCR testing revealed a more comprehensive spectrum of pathogens than previously reported, which was corroborated by the demonstration of fungal invasion on histopathology. Consistent with our current understanding, the T. rubrum complex (54.3%) are among the most common pathogens; however, a significant portion of mycology-confirmed diagnoses were caused by the T. mentagrophytes complex (6.5%), Aspergillus (7.0%) and Fusarium (4.5%). Females were significantly more likely to be infected with non-dermatophytes molds (NDMs; OR: 2.0), including Aspergillus (OR: 3.3) and Fusarium (OR: 2.0), and yeasts (OR: 1.5), including Candida albicans (OR: 2.0) and C. parapsilosis (OR 1.6), than males. The T. mentagrophytes complex became more prevalent with age, and conversely the T. rubrum complex became less prevalent with age. Patients aged ≥65 years also demonstrated a higher likelihood of contracting onychomycosis caused by NDMs (OR: 1.6), including Aspergillus (OR: 2.2), Acremonium (OR: 3.5), Scopulariopsis (OR: 2.9), Neoscytalidium (OR: 3.8), and yeasts (OR: 1.8), including C. albicans (OR: 1.9) and C. parapsilosis (OR: 1.7), than young adults. NDMs (e.g., Aspergillus and Fusarium) and yeasts were, overall, more likely to cause superficial onychomycosis and less likely to cause dystrophic onychomycosis than dermatophytes. With regards to subungual onychomycosis, Aspergillus, Scopulariopsis and Neoscytalidium had a similar likelihood as dermatophytes. The advent of molecular diagnostics enabling a timely and accurate pathogen identification can better inform healthcare providers of appropriate treatment selections and develop evidence-based recommendations.

Efficacy of Amorolfine in Onychomycosis Treatment: A Mixed-Effects Models and Multivariate Logistic Regression Analysis

BACKGROUND

Onychomycosis (OM) is a common nail infection treated with amorolfine hydrochloride nail lacquer in China. Monitoring drug concentrations and using dermoscopy to evaluate treatment efficacy may provide new insights.

OBJECTIVE

The study aims to analyse amorolfine concentrations in nails with mild to moderate OM, assess treatment outcomes using dermoscopy and explore factors influencing drug concentrations and efficacy.

METHODS

Patients with mild to moderate OM confirmed by fungal microscopy were enrolled. Amorolfine nail lacquer was applied twice weekly for 36 weeks. Monthly nail samples measured amorolfine concentrations using liquid chromatography. Dermoscopy was performed before and after treatment to evaluate responses. Mixed-effects models and logistic regression analysed factors affecting drug concentrations and outcomes.

RESULTS

Ninety-seven nails were included. Amorolfine concentrations increased over time, with higher levels in females, fingernails, 2nd-5th digits and superficial white OM (p < 0.05). Age was a risk factor, while drug concentration and OM type were protective for clinical efficacy (p < 0.05). Peak concentration correlated with clinical (r = 0.487, p = 0.000) and mycological (r = 0.433, p = 0.000) responses. Dermoscopic features improved significantly in successful cases (p < 0.05).

LIMITATIONS

In the assessment of fungal efficacy, only fungal microscopy was used, and fungal cultures were not performed. The study was limited by a small sample size and the lack of a longer follow-up to assess relapse.

CONCLUSION

Amorolfine concentrations vary with patient and nail characteristics, influencing efficacy. Dermoscopy is valuable for monitoring OM treatment.

The Emergence of N. sativa L. as a Green Antifungal Agent

BACKGROUND

Nigella sativa L. has been widely used in the Unani, Ayurveda, Chinese, and Arabic medicine systems and has a long history of medicinal and folk uses. Several phytoconstituents of the plant are reported to have excellent therapeutic properties. In-vitro and in-vivo studies have revealed that seed oil and thymoquinone have excellent inhibitory efficacy on a wide range of both pathogenic and non-pathogenic fungi.

OBJECTIVE

The present review aims to undertake a comprehensive and systematic evaluation of the antifungal effects of different phytochemical constituents of black cumin.

METHOD

An exhaustive database retrieval was conducted on PubMed, Scopus, ISI Web of Science, SciFinder, Google Scholar, and CABI to collect scientific information about the antifungal activity of N. sativa L. with 1990 to 2023 as a reference range using 'Nigella sativa,' 'Nigella oil,' 'antifungal uses,' 'dermatophytic fungi,' 'candidiasis,' 'anti-aflatoxin,' 'anti-biofilm' and 'biological activity' as the keywords.

RESULTS

Black cumin seeds, as well as the extract of aerial parts, were found to exhibit strong antifungal activity against a wide range of fungi. Among the active compounds, thymoquinone exhibited the most potent antifungal effect. Several recent studies proved that black cumin inhibits biofilm formation and growth.

CONCLUSION

The review provides an in-depth analysis of the antifungal activity of black cumin. This work emphasizes the need to expand studies on this plant to exploit its antifungal properties for biomedical applications.

Performance of Two Extracts Derived from Propolis on Mature Biofilm Produced by Candida albicans

Species of the Candida genus represent the third most common cause of onychomycosis, the most frequent and difficult to treat nail infection. Onychomycosis has been attributed to fungi organized in biofilm and some natural products have proved promising for its treatment. This study aimed to evaluate the antibiofilm activity of propolis extract (PE) and its by-product (WPE) on 7-day preformed biofilms produced by Candida albicans in polystyrene microplates, as well as in an ex vivo model on human nail fragments. The cytotoxicity and permeation capacity were also assessed. Firstly, multiple parameters were evaluated over 7 days to elucidate the dynamics of biofilm formation by C. albicans. The cell viability and total biomass did not vary much from the beginning; however, days 3 and 4 were crucial in terms of metabolic activity, which was significantly increased, and the levels of extracellular matrix components, wherein proteins and nucleic acids experienced an increase, but polysaccharide levels dropped. Architecturally, one-day biofilm showed a monolayer of organized cells (blastoconidia, hyphae, and pseudohyphae), while in the seven-day biofilm there was a three-dimensional well-structured and complex biofilm. This yeast was also able to form a biofilm on both surfaces of the nail, without an additional nutritional source. Both extracts showed excellent antibiofilm activity against the 7-day preformed biofilm and were not toxic to Vero cells at concentrations compatible with the antifungal and antibiofilm activities. Both extracts permeated the experimentally infected nail, with WPE being more efficient. The results of this study, taken together, reinforce the potential of these natural products, containing propolis, as a safe option for the topical treatment of onychomycosis.

Clinical significance of Candida isolation from dystrophic fingernails

BACKGROUND

Candida onychomycosis mostly involves fingernails. Yet, in contrast to dermatophytes, Candida isolation from dystrophic fingernails does not prove casualty, as sample contamination and non-pathogenic Candida growth occur. Characterising treatment outcome of Candida-positive dystrophic nails is crucial to avoid unnecessary treatment.

OBJECTIVE

To investigate predicators associated with treatment outcome among Candida-positive dystrophic fingernails.

PATIENTS AND METHODS

A retrospective cohort study was carried out among 108 adults with Candida-positive dystrophic fingernails not cured with adequate systemic anti-fungal course. Diagnosis was based on a single mycological culture. Patients with treatment failure (n = 85; 78.7% of the cases) were compared to patients with partial response (mild to almost cure; n = 23; 21.3% of the cases) at 9 to 12 months following treatment initiation.

RESULTS

Treatment failure was significantly associated with primary onycholysis (odds ratio [OR] 2.8; 95% confidence interval [CI] 1.1-7.4) and prolonged dystrophy (12.8 vs. 3.7 years in average), compared to partial treatment response. Non-responders had lower odds to present with distal lateral subungual onychomycosis, compared to partial responders (OR 0.3; 95% CI 0.1-0.7). Demographic and mycological characteristics, as well as number of nails affected, co-presence of paronychia, and treatment regime were not found to be associated with treatment response.

CONCLUSION

Candida-positive primary onycholysis was shown to be non-responsive to systemic anti-fungal treatment, suggesting that anti-fungal treatment is not indicated. For other clinical scenarios, high proportions of treatment non-response suggest that determining causality of Candida should not be based on a single positive mycological culture.