[Otomycosis: the modern view of etiology and management]

[Efficacy and safety of topical combination therapy in patients with acute otitis externa]

AIM

To study the structure of the microbial landscape in patients with acute otitis externa, as well as to evaluate the efficacy and safety of the combined drug chloramphenicol/clotrimazole/beclomethasone/lidocaine (Candibiotic) as an empirical therapy of this disease.

MATERIALS AND METHODS

In this retrospective study of real clinical practice, outpatient records of 963 patients who applied to the KDO of the Sverzhevsky Research Clinical Institute of Otorhinolaryngology with symptoms of otitis externa in the period from 2017 to 2022 were selected. Additional analysis was carried out on the clinical records of patients who received the combined drug Candibiotic. The endpoints of this analysis included data on the clinical and microbiological efficacy of therapy, as well as safety information.

RESULTS

According to microbiological testing, 60.6% of microorganisms belonged to bacterial flora, 26% were bacterial-fungal associations, 11.6% were monofungal flora, in 1.8% of cases there was no growth of microorganisms. The most frequently isolated microorganisms were: Pseudomonas spp (n=291; 29.16%), Staphylococcus spp. (n=214; 21.4%), Candida spp. (n=194; 19.4%), Aspergillus spp. (n=133; 13.3%). Most of the patients (71.0%) received Candibiotic. In 69.7% of patients, the resolution of the clinical symptoms of otitis externa occurred within 7 days of therapy with Candibiotic. Complete eradication of microorganisms occurred in 87% of cases. Adverse events were recorded only in 3 (0.04%) cases.

CONCLUSION

The study demonstrated an extremely high level of clinical efficacy and safety of therapy in patients with acute external infectious otitis who received the Candibiotic, which can be used as an initial empirical therapy in patients with otitis externa.

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.

In Vitro Combination of Terbinafine with Ketoconazole Against Aspergillus Species with Terbinafine High MIC Values Isolated From Otomycosis

Otomycosis is a common mycotic infection of the external auditory canal, and Aspergillus species are one of the most frequent causative agents worldwide. The limited antifungal arsenal, the high toxicity and side effects of antifungal agents, and the growing resistance to the currently available antifungals underscore the need for new therapeutic strategies. The present study aimed to evaluate the combined in vitro efficacy of terbinafine and ketoconazole against Aspergillus species with terbinafine high MIC values isolated from patients with otomycosis.84 Aspergillus species with high MIC values to terbinafine (≥ 4 µg/ml), consisting of A. flavus, A. tubingensis, A. niger, and A. terreus, were included in this study. The checkerboard microdilution method evaluated the in vitro interactions using the CLSI reference technique. Synergistic effects were observed for 66.67% (56/84) of all isolates (FICI ranging from 0.19 to 0.5). However, the interactions of terbinafine and ketoconazole exhibited indifference in 33.33% (28/84) of the isolates, and no antagonism was observed for any combination. The interaction of terbinafine and ketoconazole showed synergistic activity against Aspergillus species with high MIC values, suggesting that this is an alternative and promising approach for treating otomycosis.

Clinical Presentations, Cluster Analysis and Laboratory-Based Investigation of Aspergillus Otomycosis—A Single Center Experience

Species of Aspergillus (A.) niger complex and A. flavus complex are predominant molds that are causative agents of otomycoses. The goal of this study was to investigate the clinical presentation, diagnostic procedure, and appearance of relapse in patients with Aspergillus-otomycosis, as well as to determine the biofilm production ability of species isolated in relapse. Thirty patients with laboratory evidenced Aspergillus-otomycosis followed by two check-ups (30 and 60 days after initiation of treatment with antimycotics for local application) were included in the study. For isolation and identification of Aspergillus spp. the standard mycological procedure was applied. Results showed very high sensitivity of microscopy, but 16.7% Aspergillus species required the optimal temperature of 27–28 °C for cultivation. Applied statistical cluster analysis showed a defined specific cluster/group of patients with A. niger complex-otomycosis. Sixty days after diagnosis and treatment initiation, six patients had a relapse, with the same species of Aspergillus genus being the cause. To establish the ability of biofilm production, the modified method described by Pierce and Kvasničková was performed, and all six species isolated in the relapse episode had the ability to produce biofilm. Official criteria and recommendations are needed due to the possibility of misdiagnosis, which leads to the prolongation and complication of the disease.

[Treatment of chronic eczematous otitis externa]

Otitis externa is a common disease. The article discusses the anatomical and physiological features of the structure of the outer ear, the epidemiology of otitis externa. Acute inflammation is characterized by the presence of significant microflora, and most often it is preceded by the impact of various physical factors. With chronic inflammation, more changes from the skin are recorded, while the microflora is not always isolated. The authors consider the problem of chronic inflammation of the outer ear. They provide their own data on the etiology of inflammation. Particular attention is paid to local treatment, including their own experience of using the combined drug Candiderm. As a result of the treatment, the skin changes of the external auditory canal were completely resolved in all patients by day 28, the itching in the ears completely stopped after 10-14 days of therapy. Stable remission was achieved in 89% of patients.

[Modern aspects of inflammatory external ear diseases treatment]

The article deals with the problem of inflammatory diseases of the external ear. A review of pruritic dermatoses of the external auditory canal was carried out. It has been shown that in chronic dermatoses, the contamination of the skin with bacterial and fungal pathogens significantly increases, which leads to a high risk of developing secondary infectious pathological processes. Treatment of dermatological inflammatory ear diseases includes careful daily hygiene of the external auditory canal and pharmacotherapy, a key aspect of which is the use of topical etiotropic, anti-inflammatory, and symptomatic drugs. The advantage of the combined drug candiderm is described, which, thanks to the unique combination of beclomethasone, gentamicin and clotrimazole in the composition, effectively relieves the symptoms of external ear dermatoses.

[Symptomatic approach to diagnosis and treatment of inflammatory diseases of the outer ear]

The article presents a modern approach to the diagnosis and treatment of inflammatory diseases of the outer ear. The authors consider the main predisposing factors that determine the development of external otitis: traumatic injury, water ingress, use of in-the-ear headphones, occupational hazards and others. The role of various microorganisms, including Pseudomonas aeruginosa, Staphylococcus aureus, bacteria of Enterobacteriaceae family and fungi of genera Aspergillus, Candida, Penicillium, Mucor in the genesis of inflammatory pathology of the outer ear is discussed. For the purpose of effective treatment of external otitis the authors suggest to use a local combined preparation Candibiotic, which contains antibacterial, fungicidal, hormonal and analgesic components that affect the main factors of pathogenesis of the disease.