Pharyngomycosis

Pharyngomycosis (tonsillomycosis, fungal infection of the oral cavity, fungal pharyngitis, fungal tonsillitis, fungal infection of the pharynx, thrush) is pharyngitis (tonsillitis) caused by fungi. Pharyngitis is an inflammation of the mucous membrane of the oropharynx. Tonsillitis is an inflammation of one or more lymphoid formations of the pharyngeal colon, most often the palatine tonsils. In most cases, the disease is caused by yeast-like fungi, less often mold fungi.

[ 1 ], [ 2 ], [ 3 ], [ 4 ]

Epidemiology

The incidence of pharyngomycosis has increased sharply over the past 10 years and accounts for 30-45% of infectious lesions of the pharynx and tonsils. The increase in the number of patients with this pathology is due to a significant increase in the number of risk factors for their development, among which the leading positions are iatrogenic immunodeficiency states that arise as a result of massive antibacterial therapy, long-term use of glucocorticoid and immunosuppressive drugs in oncological diseases, blood diseases, HIV infection, endocrinopathies. In such situations, there are all the prerequisites for the development of pharyngomycosis, since the causative agents of the disease are opportunistic fungi that saprophyte on the mucous membrane of the oropharynx and in the environment.

The problem of pharyngomycosis is acquiring important social significance not only due to its ever-widening prevalence, but also because fungal infection of the oropharynx is more severe than other inflammatory processes of this localization. Fungal infection of the oropharynx can become the primary focus of disseminated visceral mycosis or the cause of fungal sepsis.

In childhood, the incidence of pharyngomycosis is high. Candidiasis of the oral mucosa is especially common in newborns (thrush). The occurrence of candidiasis is associated with the incomplete formation of immune protection in newborns from the effects of mycotic infection. Older children often suffer from pharyngomycosis. In many of them, the onset of the disease is associated with fungal infection at an early age and incomplete elimination of the pathogen from the source of infection.

In the adult population, mycosis of the pharynx is diagnosed with the same frequency at the age of 16 to 70 years, and in some cases at an older age.

Causes pharyngomycosis

The main causative agents of pharyngomycosis are considered to be various species of yeast-like fungi of the genus Candida (in 93% of cases): C. albicans, C. tropicalis, C. krusei, C. glabrata, C. parapsillosis, C. stellatoidea, C. intermedia, C. brumpti, C. sake, etc. The main causative agent is considered to be C. albicans (in 50% of cases), in second place in terms of frequency of occurrence is C. stellatoidea. This species is close to C. albicans in its morphological and biochemical properties, and many authors identify them.

In 5% of cases, fungal infections of the oropharynx are caused by mold fungi of the genera Geotrichum, Aspergillus, Penicillium, etc.

[ 5 ], [ 6 ], [ 7 ], [ 8 ]

Risk factors

The development of the disease is facilitated by long-term use of antibiotics, corticosteroids, cytostatics, injuries and chronic inflammatory processes in the throat, diabetes mellitus, tuberculosis, hypo- and avitaminosis.

[ 9 ], [ 10 ]

Pathogenesis

The main causative agents of pharyngomycosis are considered to be various species of yeast-like fungi of the genus Candida (in 93% of cases): C. albicans, C. tropicalis, C. krusei, C. glabrata, C. parapsillosis, C. stellatoidea, C. intermedia, C. brumpti, C. sake, etc. The main causative agent is considered to be C. albicans (in 50% of cases), in second place in terms of frequency of occurrence is C. stellatoidea. This species is close to C. albicans in its morphological and biochemical properties, and many authors identify them.

In 5% of cases, fungal infections of the oropharynx are caused by mold fungi of the genera Geotrichum, Aspergillus, Penicillium, etc.

Symptoms pharyngomycosis

With pharyngomycosis, patients complain of discomfort in the throat, a burning sensation, dryness, soreness, and irritation, which are more pronounced than with bacterial pharyngeal infection. The pain is moderate in intensity, and increases with swallowing and eating irritating food. Patients note pain radiating to the submandibular region, the anterior surface of the neck, and the ear. Specific signs of pharyngomycosis include the detection of plaque, swelling of the mucous membrane, and pronounced intoxication. Pharyngomycosis is also characterized by frequent exacerbations (2-10 times a year) and the development of the disease at any age.

The clinical course of pharyngomycosis can be acute and chronic. The process is localized mainly on the palatine tonsils, palatine arches, and the back wall of the pharynx. Patients experience a sensation of scratching, burning, and discomfort in the throat, malaise, headache, and subfebrile body temperature. In pharyngomycosis caused by yeast-like fungi, whitish plaques of varying sizes are found in the throat, which are easily removed, exposing hyperemic areas of the mucous membrane, and less often bleeding ulcers. Pharyngomycosis caused by mold fungi is characterized by the fact that the plaques are yellowish in color and are difficult to remove, which may raise suspicion of diphtheria of the pharynx. Fungi may spread to the larynx, esophagus, and form paratonsillar abscesses.

[ 11 ], [ 12 ]

Forms

Depending on the localization of the mycotic lesion, the following are distinguished:

• cheilitis;
• glossitis;
• stomatitis;
• gingivitis;
• tonsillitis;
• pharyngitis.

According to the clinical course, the following forms of pharyngomycosis are distinguished:

• acute:
• chronic.

In many cases, the acute process becomes chronic due to incorrect diagnosis and irrational treatment.

Clinical and morphological variants of pharyngomycosis:

• pseudomembranous. It is characterized by white, cheesy deposits that peel off to reveal a bright red base, sometimes with a bleeding surface:
• erythematous (catarrhal). Characterized by erythema with a smooth "varnished" surface, while patients note pain, burning, dryness in the oral cavity;
• hyperplastic. White spots and plaques are found in the oral cavity, which are difficult to separate from the underlying epithelium;
• erosive-ulcerative.

[ 13 ], [ 14 ]

Diagnostics pharyngomycosis

The following data must be taken into account during the survey: the time of onset of the disease, the characteristics of the course. It is necessary to find out whether the patient has previously had paratonsillitis and paratonsillar abscesses, the frequency, duration and nature of exacerbations of tonsillitis. Previously conducted treatment (local or general), its effectiveness are taken into account. It is necessary to find out whether the patient was treated with antibiotics, glucocorticoids, cytostatics (duration and intensity of treatment), the characteristics of industrial and domestic conditions, previous diseases, allergic anamnesis. It should be borne in mind that patients with pharyngomycosis have frequent exacerbations, no or insignificant effect from standard treatment methods.

[ 15 ], [ 16 ]

Physical examination

During examination, the following morphological changes are detected: infiltration of the mucous membrane, dilation and injection of blood vessels, and desquamation of the epithelium. A characteristic clinical sign of chronic pharyngitis of fungal etiology is considered to be uneven hyperemia and infiltration of the mucous membrane of the posterior pharyngeal wall. Against the background of subatrophy, an increase in lateral ridges is noted. Often, against the background of the described pathological changes, whitish cheesy easily removable plaques are detected, under which areas of erosion of the mucous membrane are found. In the ulcerative-necrotic form of fungal tonsillitis, plaques extend beyond the palatine tonsils to the palatine arches and soft, and sometimes hard palate. Detection of plaques and one-sided damage are considered pathognomonic diagnostic signs of pharyngomycosis.

In case of chronic tonsillitis, an examination is carried out outside the period of exacerbation. It is necessary to pay attention to the color of the mucous membrane of the oropharynx, tonsils, the nature of plaque (their color, prevalence), the size of the tonsils, the degree of swelling, consistency (dense or loose), adhesion to the arches, the presence of purulent contents in the lacunae. It is necessary to examine the lingual tonsil (pay attention to its color, size, the presence of plaque), lymph nodes.

[ 17 ]

Laboratory research

Fungal infection of the pharynx may be suspected based on endoscopic examination data, but mycological laboratory research methods are crucial for establishing the correct diagnosis. 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 repeated studies of the pathological discharge. At the same time, a single growth of fungi in the culture does not always indicate a fungal infection.

Mycological examination involves microscopy and then sowing of pathological discharge on nutrient media. For accurate diagnosis, it is important to correctly collect pathological material for examination. Plaques from the surface of the tonsils are usually easily removed. Large, dense plaques are removed onto a slide using ear tweezers and, without smearing, covered with another slide. Scanty plaques are removed using a Volkmam spoon, carefully so as not to injure the tissue.

In tonsil candidiasis, microscopic examinations of both native and stained specimens are important. Romanovsky-Giemsa staining reveals spores of yeast-like fungi of the genus Candida. The fungal cells are round or elongated, the budding process is clearly visible, as well as the threads of pseudomycelium. The mycelium of yeast-like fungi of the genus Candida consists of bundles of elongated cells connected in chains that resemble true mycelium. True mycelium is a long tube divided by transverse partitions with a single membrane. Pseudomycelium does not have a common membrane. Morphological features of the pseudomycelium of the fungus of the genus Candida are considered one of the reliable features that distinguish it from other fungi.

At the initial stage of the disease, microscopic examination of the plaque reveals clusters of fungal blastospores, and pseudomycelium threads are single or absent. At the height of the disease, clusters of budding fungal cells and numerous pseudomycelium threads are visible in the smear. Thus, an accurate diagnosis can be established based on microscopic examination data.

Culture studies are considered one of the important methods of diagnosing candidiasis. With the help of these methods, not only the diagnosis of fungal disease is confirmed, but also the type of pathogen is determined, and the effectiveness of treatment is judged.

When seeding on elective media in patients with pharyngomycosis, yeast-like fungi of the genus Candida are most often isolated. When seeding on solid Sabouraud medium, uniform growth of yeast-like fungi of the genus Candida is observed at each seeding point (to avoid errors, seeding is performed in 2-4 test tubes).

In chronic tonsillitis, when there is no plaque, the sowing is done as follows. The material for sowing is taken from both tonsils and the back wall of the pharynx with a sterile cotton swab. The swabs are placed in sterile test tubes with liquid Sabouraud medium, and then in a thermostat for 24 hours at an ambient temperature of 27-28 C. After this, the material is reseeded onto solid Sabouraud medium simultaneously in 3 test tubes. After reseeding, the test tubes are again placed in the thermostat for 8-10 days. Already on the 4-5th day, Candida fungi give a characteristic growth of colonies that are round, white or whitish-gray, their surface is convex, smooth and shiny, the consistency is cheesy.

If fungi are found in tonsil deposits during microscopic examination, they can also be isolated by sowing in pure culture. As a rule, continuous growth is noted (30-45 thousand colonies in 1 ml).

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

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

• clinical data;
• detection of fungi by microscopy of smears from the mucous membrane;
• positive results when cultured on elective nutrient media.

[ 18 ], [ 19 ], [ 20 ], [ 21 ], [ 22 ]

Screening

The screening method for detecting pharyngomycosis is microscopy of a native and stained smear preparation from the mucous membrane of the pharynx and the surface of the tonsils.

Differential diagnosis

Differential diagnostics should be carried out with acute bacterial pharyngitis and tonsillitis, scarlet fever, diphtheria, tuberculosis, syphilis, angina form of infectious mononucleosis, Simanovsky-Plaut-Vincent's angina, and malignant neoplasms.

[ 23 ], [ 24 ]

Indications for consultation with other specialists

A consultation with an immunologist is required to identify and correct immunodeficiency conditions; an endocrinologist - to identify endocrine pathology, correct endocrinopathies; an oncologist - to exclude neoplasms of the oral cavity and pharynx; an infectious disease specialist - to exclude diphtheria and mononucleosis.

Treatment pharyngomycosis

Treatment is aimed at eliminating the causative fungus and correcting the immunodeficiency state.

Indications for hospitalization

Complicated forms of pharyngomycosis.

[ 25 ], [ 26 ], [ 27 ], [ 28 ]

Drug treatment of pharyngomycosis

General principles of pharmacotherapy of fungal infections of the oropharynx:

• The use of systemic antifungal drugs must be combined with local action on the source of infection;
• Antifungal drug therapy should be based on the results of laboratory testing of the fungus's sensitivity to the drug used.

Treatment of pharyngomycosis consists of prescribing the following medications: nystatin in tablets, which are chewed and the resulting mass is applied to the surface of the pharynx by tongue movements and swallowing movements. If ineffective - levorin, dekamin. The lesions are lubricated with a 1% solution of gentian violet, 10% solution of sodium tetraborate in glycerin, Lugol's solution.

If treatment with standard doses of fluconazole is ineffective, itraconazole is prescribed at 100 mg per day or ketoconazole at 200 mg per day for a month. Itraconazole acts not only on yeast-like fungi of the genus Candida, but also on mold fungi.

In case of pharyngomycosis resistant to other antimycotics, amphotericin B is administered intravenously at 0.3 mg/kg per day for 3-7 days. Treatment of pharyngomycosis with amphotericin B and ketoconazole is carried out under the control of biochemical parameters of liver and kidney function, since these drugs, especially amphotericin B, have a pronounced nephro- and hepatotoxic effect.

In systemic therapy of pharyngomycosis, drugs from the following groups of antimycotics are used:

• polyenes: amphotericin B, nystatin, levorin, natamycin:
• azoles: fluconazole, itraconazole, ketoconazole;
• allylamines: terbinafine.

The most effective for pharyngomycosis is fluconazole, which is prescribed once a day at a dose of 50 or 100 mg, in severe cases - 200 mg. The course of treatment is 7-14 days.

Alternative treatment regimens for pharyngomycosis, also lasting 7-14 days, are considered to be the following:

• Levorin suspension (20,000 U/ml), 10-20 ml 3-4 times a day; Natamycin suspension (2.5%), 1 ml 4-6 times a day;
• Nystatin suspension (100,000 U/ml), 5-10 ml 4 times a day.

If treatment with standard doses of fluconazole is ineffective, itraconazole is prescribed at 100 mg per day or ketoconazole at 200 mg per day for a month. Itraconazole acts not only on yeast-like fungi of the genus Candida, but also on mold fungi.

In case of pharyngomycosis resistant to other antifungal agents, amphotericin B is administered intravenously at 0.3 mg/kg per day for 3-7 days. Treatment with amphotericin B and ketoconazole is carried out under the control of biochemical parameters of liver and kidney function, since these drugs, especially amphotericin B, have a pronounced nephro- and hepatotoxic effect.

For mold mycoses, itraconazole and terbinafine are considered the most effective. The course of treatment with itraconazole is 14 days at 100 mg once a day, with terbinafine - 8-16 days at 250 mg once a day.

For local treatment, antiseptics and antimycotics (miramistin, oxyquinoline, clotrimazole, borax in glycerin, natamycin suspension) are used for lubrication, rinsing, irrigation, and washing of the tonsil lacunae.

Antifungal drugs are used against the background of eliminating risk factors, such as neutropenia, careful treatment of dentures, etc.

Further management

In case of exacerbation of pharyngomycosis, azoles are prescribed orally or locally for 7-14 days, taking into account the drug sensitivity of the pathogen. It is necessary to eliminate risk factors. After achieving remission, anti-relapse treatment is carried out with systemic antimycotics or antifungal drugs for local use.

Prevention

The main measures for the prevention of pharyngomycosis should be aimed at eliminating the factors that contribute to the activation of fungal flora, namely, the abolition of antibiotics, glucocorticoids, correction of the glycemic profile, and general strengthening therapy.

Forecast

With timely treatment and adequate antifungal therapy, the prognosis is favorable. The approximate period of incapacity for work during exacerbation of pharyngomycosis is 7-14 days.