Successful treatment of a recurrent Aspergillus niger otomycosis with local application of voriconazole

Etiology, Predisposing Factors, Clinical Features and Diagnostic Procedure of Otomycosis: A Literature Review

Otomycosis (OM) is a superficial fungal infection of the external auditory canal (EAC) with a worldwide prevalence ranging from 9% to 30%. Commonly, otomycoses are caused by Aspergillus (A.) niger complex and Candida spp. Other causative agents are yeasts of the genera Cryptococcus spp., Rhodotorula spp., Geotrichum candidum, dermatophytes (Trichophyton mentagrophytes), and non-dermatophytes molds (Fusarium spp., Penicillium spp., Mucorales fungi). The widest range of different species causing OM are found in the territories of Iran, India, China, Egypt, Mexico, and Brazil. Fungal infection of the EAC varies from mild to severe forms. It can be acute, subacute, or chronic, and is often unilateral, while the bilateral form is more common in immunocompromised patients. From an epidemiological point of view, tropical and subtropical climates are the most significant risk factor for the development of otomycosis. Other predisposing conditions include clothing habits, EAC hygiene practices, long-term antibiotic therapy, diabetes, and immunodeficiency. Since it is often difficult to distinguish otomycosis from an infection of a different origin, laboratory-based evidence, including standard procedures (microscopy and cultivation), is essential for diagnosis. For the treatment of this superficial fungal infection, there are no official therapeutic guidelines and protocols. However, many antifungals for local application, such as polyene, imidazoles, and allylamines, can be applied, as well as systemic antimycotics (triazoles) in severe forms of infection.

Relapsing Aspergillus otomycosis despite prolonged systemic antifungal therapy and resolution after topical voriconazole administration: A case report

We report a case of intractable Aspergillus otomycosis with multiple relapses despite conventional topical and systemic antifungal treatment, and adjunctive usage of hyperbaric oxygen therapy. Of note, otomycosis relapsed even after six months of continuous systemic antifungal treatment with therapeutic drug levels and without treatment interruption; and only resolved after application of topical voriconazole. (max. 75 words).

Conventional Antifungals for Invasive Infections Delivered by Unconventional Methods; Aerosols, Irrigants, Directed Injections and Impregnated Cement

The administration of approved antifungals via unapproved formulations or administration routes (such as aerosol, direct injection, irrigation, topical formulation and antifungal-impregnated orthopedic beads or cement) may be resorted to in an attempt to optimize drug exposure while minimizing toxicities and/or drug interactions associated with conventional (systemic) administrations. Existing data regarding such administrations are mostly restricted to uncontrolled case reports of patients with diseases refractory to conventional therapies. Attribution of efficacy and tolerability is most often problematic. This review updates prior published summaries, reflecting the most recent data and its application by available prevention and treatment guidelines for invasive fungal infections. Of the various dosage forms and antifungals, perhaps none is more widely reported than the application of amphotericin B-containing aerosols for the prevention of invasive mold infections (notably Aspergillus spp.).

The adult microbiome of healthy and otitis patients: Definition of the core healthy and diseased ear microbiomes

Otitis media (OM) and externa (OE) are painful, recurrent ear conditions. As most otitis publications focus on the bacterial content of childhood ears, there remains a dearth of information regarding the adult ear microbiome including both bacteria and fungi. This study compares the outer ear microbiome of healthy adults to adults affected by OE and OM using both intergenic-transcribed-spacer (ITS) and 16S-rDNA sequencing. The adult ear core microbiome consists of the prokaryote Cutibacterium acnes and the eukaryotic Malassezia arunalokei, M. globosa, and M. restricta. The healthy ear mycobiome is dominated by Malassezia and can be divided into two groups, one dominated by M. arunalokei, the other by M. restricta. Microbiome diversity and biomass varied significantly between healthy and diseased ears, and analyses reveal the presence of a potential mutualistic, protective effect of Malassezia species and C. acnes. The healthy ear core microbiome includes the bacteria Staphylococcus capitis and S. capitis/caprae, while the diseased ear core is composed of known bacterial and fungal pathogens including Aspergillus sp., Candida sp., Pseudomonas aeruginosa, S. aureus, and Corynebacterium jeikeium. The data presented highlight the need for early detection of the cause of otitis to direct more appropriate, efficient treatments. This will improve patient outcomes and promote improved antimicrobial stewardship.

A Comparison of Triamcinolone Acetonide Econazole Cream and Nystatin Suspension in Treatment of Otomycosis

OBJECTIVES/HYPOTHESIS

To compare the efficacy and adverse effects of triamcinolone acetonide econazole cream and nystatin suspension in the treatment of otomycosis, and to determine the clinical features, predisposing factors, and etiology of otomycosis.

STUDY DESIGN

A prospective study.

METHODS

A prospective clinical trial was conducted on 786 patients diagnosed with otomycosis. The study population was randomly divided into two treatment groups of triamcinolone acetonide econazole cream (TAEC) and nystatin suspension in a 1:1 ratio. After clearing all fungal deposits in the external auditory canal, the antimycotic drugs were locally applied for at least 2 weeks. The efficacy and adverse effects were compared between the two antifungal reagents by statistical analysis. Meanwhile, patient clinical data were collected to find out the clinical features, predisposing factors, and etiology.

RESULTS

Pruritis was the most common symptom and Aspergillus niger was the leading fungal pathogen. There was high association (44.5%) of otomycosis with a history of unclean ear picking. The cure rate was 97.6% in the TAEC group and 73.5% in the nystatin group (P < .01). Treatment with TAEC resulted in 2.4% of patients complaining of discomforts (irritant dermatitis, otalgia, or headache) versus 59.8% of patients complaining discomforts treated with nystatin (P < .01). The residue rate of antifungals was 1.9% in the TAEC group and 89.9% in the nystatin group (P < .01) at the end of treatment.

CONCLUSIONS

Thoroughly cleaning of the external auditory canal followed by local use of TAEC under endotoscope is an effective, convenient, and well-tolerated treatment for otomycosis.

LEVEL OF EVIDENCE

1 Laryngoscope, 131:E1640-E1646, 2021.

Administration of 1% topical voriconazole drops was effective and safe in the treatment of refractory otomycosis without tympanic membrane perforation

BACKGROUND

Refractory otomycosis is a common condition that is difficult to treat.

OBJECTIVES

This study aimed to evaluate the effectiveness of 1% topical voriconazole drops in the treatment of otomycosis.

METHODS

This retrospective analysis was conducted from November 2017 to November 2019. Patients who had refractory otomycosis without tympanic membrane perforation confirmed by microbial culture and fluorescent staining were included in the study. All patients were treated with 1% topical voriconazole drops hourly at daytime for 2 weeks. Evaluation of effectiveness was conducted 1 month after the completion of topical voriconazole treatment. Before and after topical voriconazole treatment, hearing tests were performed in all patients.

RESULTS

Fifty-five patients were included in this study. The reasons for refractoriness were resistant recurrence to imidazole drugs (50 cases, 90.9%) and difficulty in cleaning the external auditory canal (5 cases, 9.1%). The most common strain was Aspergillus terreus (50.9%), followed by Aspergillus flavus (29.1%), Aspergillus niger (10.9%), and Aspergillus fumigatus (9.1%). After 2 weeks of treatment with 1% topical voriconazole drops, otomycosis in all patients was resolved. There was no significant change in bone conduction before and after topical voriconazole treatment (paired t-test, P = 0.5023; linear correlation analysis, R² = 0.98; equation, y = 1.003x-0.284). Adverse effects, such as blurred vision and phototoxicity, were not observed in any patient.

CONCLUSIONS

Administration of 1% topical voriconazole drops was effective and safe in the treatment of refractory otomycosis without tympanic membrane perforation within 2 weeks.

Species distribution patterns and epidemiological characteristics of otomycosis in Southeastern Serbia

INTRODUCTION

Otomycosis, a superficial fungal infection of the external auditory canal (EAC), is a disease with exceptionally high prevalence.

AIM

The aim of this study was to determine the prevalence of otomycosis, the distribution of causative species and to evaluate epidemiological characteristics of these infections.

METHODOLOGY

The patients' data were collected from record book and database of mycological examinations conducted at Public Health Institute Nis, Serbia. In the period from 2014 to 2018 samples of 1287 patients with symptoms and signs of EAC infection were investigated. Standard mycological methods were used for isolation and determination of fungi.

RESULTS

High prevalence of otomycosis was determined in examined patients (22.7%). However, the prevalence rates did not differ significantly in the studied period (p=0.931). The majority of patients were diagnosed with only unilateral EAC infection (82.9%). Considering all patients with otomycosis, mold infections caused by the genus Aspergillus (143/48.9%) were more frequent than Candida spp. ear infections (133/45.6%), with Aspergillus niger and Candida аlbicans being predominant causative agents. Mixed Aspergillus and Candida otomycosis was established in 16 (5.5%) patients. Otomycosis was more common in male subjects (26.8%, p=0.003) who also suffered from Aspergillus otomycosis more frequently (17.5%, p<0.001). The prevalence of these infections increases with age (p=0.005), while they do not show seasonal pattern (p>0.05).

CONCLUSION

Noted high prevalence of otomycosis, with both yeasts and non-dermatophyte molds acting as infectious agents which require different treatment, implies the necessity for further epidemiological monitoring of this form of superficial mycoses.

Voriconazole topical cream formulation: evidence for stability and antifungal activity

Systemic use of voriconazole (VCZ) might be restricted by adverse events, such as hepatotoxicity and neurotoxicity, or drug-drug interactions. Topical VCZ application to skin may help to treat local infection more effectively and limit unwanted whole-body exposure. Topical VCZ cream was stable for 90 days when refrigerated. A patient with cutaneous Fusarium solani infection on his right forearm was successfully treated with topical 1% VCZ cream after failure of oral VCZ treatment.

Species Distribution and Comparison between EUCAST and Gradient Concentration Strips Methods for Antifungal Susceptibility Testing of 112 Aspergillus Section Nigri Isolates

Aspergillus niger, the third species responsible for invasive aspergillosis, has been considered as a homogeneous species until DNA-based identification uncovered many cryptic species. These species have been recently reclassified into the Aspergillus section Nigri However, little is yet known among the section Nigri about the species distribution and the antifungal susceptibility pattern of each cryptic species. A total of 112 clinical isolates collected from 5 teaching hospitals in France and phenotypically identified as A. niger were analyzed. Identification to the species level was carried out by nucleotide sequence analysis. The MICs of itraconazole, voriconazole, posaconazole, isavuconazole, and amphotericin B were determined by both the EUCAST and gradient concentration strip methods. Aspergillus tubingensis (n = 51, 45.5%) and Aspergillus welwitschiae (n = 50, 44.6%) were the most common species while A. niger accounted for only 6.3% (n = 7). The MICs of azole drugs were higher for A. tubingensis than for A. welwitschiae The MIC of amphotericin B was 2 mg/liter or less for all isolates. Importantly, MICs determined by EUCAST showed no correlation with those determined by the gradient concentration strip method, with the latter being lower than the former (Spearman's rank correlation tests ranging from 0.01 to 0.25 depending on the antifungal agent; P > 0.4). In conclusion, A. niger should be considered as a minority species in the section Nigri The differences in MICs between species for different azoles underline the importance of accurate identification. Significant divergences in the determination of MIC between EUCAST and the gradient concentration strip methods require further investigation.

Antifungal susceptibility profiles of otomycosis etiological agents in Ahvaz, Iran

Background and Purpose

Otomycosis is a secondary ear fungal infection among predisposed individuals in humid conditions. Aspergillus species are the most common etiologic agents of this infection. Several ototopical antifungals are currently used for the treatment of this disease; however, recurrence and treatment failure are usually observed in some cases. Regarding this, the present study was conducted to investigate the antifungal activity of caspofungin, azoles, and terbinafine against the isolated agents of otomycosis.

Materials and Methods

This study was conducted on the specimens collected from 90 patients with otomycosis. The samples were cultured on Sabouraud dextrose agar and identified based on morphological characteristics, physiological tests, and microscopic features. Furthermore, the microdilution method was used for antifungal susceptibility testing according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Finally, the minimum inhibitory concentration (MIC) and minimum effective concentration (MEC) ranges, MIC/MEC₅₀, MIC/MEC₉₀, and geometric mean (GM) MIC/MEC were calculated for the isolates.

Results

According to the results, 77 patients with otomycosis were positive for different Aspergillus (88.3%) and Candida (11.7%) species. Aspergillus niger complex (n=36) was found to be the most common agent, followed by A. flavus, A. terreus, and A. nidulans complexes. Furthermore, epidemiological cutoff values (ECVs) were lower than those presented by the CLSI for itraconazole and caspofungin in 98.5% and 42.6% of Aspergillus species, respectively. Terbinafine exhibited a great activity against Aspergillus species, while fluconazole revealed a low activity against both Aspergillus species. Based on the results, 77.8% of Candida species were resistant to caspofungin; however, miconazole and econazole had low MIC ranges.

Conclusion

Aspergillus niger and A. flavus complexes were identified as the most common agents accounting for 85.7% of the isolates. In addition, terbinafine was identified as the best antifungal for both Aspergillus and Candida species. Moreover, tested azoles had relatively low MICs, whereas most of the isolates had the MIC values beyond the caspofungin ECVs.