Otomycosis - Diagnosis

When interviewing, it is necessary to pay attention to the time of onset of the disease and the characteristics of its course. It is necessary to find out from the patient whether he has previously had otitis mycosis of another localization, the frequency, duration and nature of exacerbation.

Previous treatment (local or general), its effectiveness, and whether the condition has worsened are taken into account. It is necessary to find out whether the patient was treated with antibiotics, glucocorticoids, cytostatic drugs (duration and intensity of treatment), the specifics of working and living conditions, previous illnesses, and allergy history. Patients with otomycosis experience an increase in the frequency of exacerbations, and the absence or negative effect of standard treatment methods.

Physical examination

In penicilliosis, the process is usually localized in the cartilaginous part of the external auditory canal. Moderate infiltration of the skin of the external auditory canal is noted, which does not lead to its complete closure. The eardrum is hyperemic in most cases, sometimes its surface is hyperemic, there may be protrusions on it, which creates a false impression of perforation.

Characteristic and specific for penicillium lesions of the outer ear is considered to be the type of pathological discharge, which has various shades of yellow and in some cases resembles earwax. Pathological discharge is found throughout the entire length of the external auditory canal. Dry crusts and films are often found during examination.

In aspergillosis, the external auditory canal is also narrowed due to infiltration of the walls, but unlike penicillosis, skin infiltration is more pronounced in the bone section. In almost all cases, the eardrum is involved in the process, its infiltration, thickening, and disappearance of identification marks are noted. In some cases, granulation is detected. Pathological discharge in aspergillosis is more abundant than in penicillosis and differs in color. In most cases, it is of various shades of gray, sometimes with black dots, can be cholesteatoma- or sulfur-like, resembles a wet newspaper.

In case of candidal lesion of the external auditory canal, moderate narrowing of the external auditory canal is observed, more pronounced in the cartilaginous part, the eardrum is hyperemic. Pathological discharge is more liquid in consistency than in mold mycosis, more often whitish in color and of a cheesy consistency. The process often spreads to the skin of the outer ear.

Laboratory research

Fungal infection may be suspected based on the results of an otolaryngological examination, but mycological laboratory methods of research are of decisive importance. At the same time, single negative results do not indicate the absence of a fungal disease, so in such a situation it is necessary to conduct a repeated study of the pathological discharge. At the same time, a single growth of fungi in the culture does not always indicate a fungal infection.

To collect samples of biological material for mycological examination, an attic probe or a Volkman spoon is used. Pathological discharge should preferably be collected from the deep sections of the external auditory canal. Pathological material is placed between two sterile degreased slides and examined under a microscope under 100-, 200-, 400-fold magnification. In addition to microscopy of native material, microscopic examination of preparations stained according to Romanovsky-Gimee is carried out. Microscopic examination is considered the most informative and reliable method for identifying the causative agent of the disease.

For mycological diagnostics, pathological material is seeded on elective media (Saburo, Chapek, etc.). Yeast-like fungi of the genus Candida are determined by morphological features and the nature of sugar fermentation. The material is seeded in test tubes, in 9 seeding points, after which the seedings are placed in a thermostat at an ambient temperature of 27-30 °C. After 6-7 days, if the fungus is present, continuous growth of the pathogen is observed in all seeding points, while uniform growth of one type of fungi is detected in all test tubes.

The Candida albicans fungus is determined using an accelerated method: the test material, presumably containing Candida fungi, is added with a loop to 1 ml of human, rabbit or horse blood serum, after which the test tube is placed in a thermostat at an ambient temperature of 37 °C for 24 hours. After 24 hours, a drop is applied from the test tube to a glass slide and the preparation is examined under a microscope at 200x magnification. If the Candida albicans fungus is present in the medium, the so-called germ tubes extending from the cell, characteristic only of this type of fungi, will be clearly visible under the microscope.

Differential diagnosis of fungal otitis

Thus, the diagnosis of fungal ear infection is made on the basis of:

• clinical data;
• detection of fungal structures during smear microscopy:
• positive results of cultures on elective media.

In addition, clinical blood tests (including for HIV infection, hepatitis markers, syphilis), urine tests, determination of blood glucose levels, and immunogram indicators are required.

Differential diagnosis must be carried out with bacterial otitis, allergic otitis, eczema, ear tumors and other inflammatory processes of the outer and middle ear.

Indications for consultation with other specialists

A consultation with an immunologist is required to identify and correct immunodeficiency states, a consultation with an endocrinologist is required to identify endocrine pathology and correct endocrinopathies.

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