Mycoses methods of microbiological diagnosis of mycoses. Laboratory diagnosis of fungal diseases
Laboratory diagnosis of fungal diseases is based on detecting the fungus and determining its genus and species. It consists of two main stages: microscopic and cultural studies.
Microscopic examination
Microscopic examination is the first and important link in confirming the preliminary diagnosis.
The success of microscopic examination largely depends on the correct collection of pathological material. For microscopic examination, it is necessary to select hair that has visible signs of fungal damage (dull, broken, thickened). Hair that has changed in appearance is removed with epilation tweezers. To detect single affected hairs with microsporia, you can use a fluorescent lamp with a Wood filter (greenish-blue glow).
When selecting affected hair, a number of additional characteristics can be used. Hair affected by microsporums has a gray sheath of externally located spores at the base. In case of chronic trichophytosis, short gray affected hairs, curved in the form of “commas” and “question marks,” as well as “black dots” (thickened black affected hairs broken off at the mouth of the follicle) are found in the thickness of the scales. In case of infiltrative-suppurative trichophytosis, for microscopic examination, in addition to the affected hair, you can use pus and crusts from the lesion.
From skin lesions with microsporia, trichophytosis and mycosis of inguinal folds, scales must be scraped off from the peripheral zone of the lesion, where the fungus is found in larger quantities. The vellus hair is scraped off along with the skin flakes.
When examining affected hair with microsporia and trichophytosis, attention is paid to the location of the spores (inside or outside the hair) and their size. These data make it possible in some cases to clarify the diagnosis, clinical form of mycosis and epidemiology.
In the interdigital form of mycosis of the feet, skin scales and scraps of the macerated stratum corneum are used for microscopic examination. The area of the nail that needs to be taken for microscopic examination depends on the form of onychomycosis. With a superficial form, it is necessary to scrape the surface of the nail plate.
In the most common distal-lateral form, a scraping is used from the nail bed, from under the plate (subungual hyperkeratosis) with a part of the cut off altered nail plate. For the proximal subungual form, special methods are used to collect material (drilling windows using a drill, nail biopsy).
In the squamous-hyperkeratotic form of mycosis of the feet, the scales are scraped off from the plantar surface. In the dyshidrotic form of mycosis of the feet, the covers of the blisters are cut off for examination.
Technique for preparing material for microscopic examination of hair . A small drop of 30% KOH is applied to a glass slide and the affected hair is placed into it with a dissecting needle. The drop with the hair is slightly heated over the flame of an alcohol lamp until vapor appears above the surface of the liquid or a rim of crystals falls out along the edge of the drop of alkali. After covering with a coverslip, excess alkali is removed with filter paper. The drug is examined first under low and then under high (x 400) microscope magnification.
Skin and nail scales . Thin nail scales for microscopic examination are placed on a glass slide in a drop of 30% KOH and heated, adding alkali as it evaporates. The cooled, unstained specimen is covered with a coverslip and examined under a microscope.
Thick skin and nail scales are placed in a centrifuge tube and filled with a few drops of 30% KOH. The test tube is heated to a boil and left for 20-30 minutes. Part of the softened material is transferred to a glass slide with a glass rod, pressing with a match until a “cloud” appears, after which it is examined under a microscope.
Pus . A drop of pus is mixed with a drop of alcohol and half-and-half glycerin and examined in a native preparation.
Cultural diagnostics
Cultural diagnostics are carried out to definitively clarify the diagnosis and clarify the epidemiology. It involves obtaining a culture of the fungus followed by microscopic examination.
Affected hair, scales (skin and nail), blisters or pus are inoculated on an artificial nutrient medium. By the appearance of giant colonies on Petri dishes, one can get an idea of the genus of the pathogen (Microsporum, Trichophyton, Epidermophyton), its type (L. canis or ferrugineum, T. violaceum, verrucosum or gypseum). Final clarification of the genus and species of the fungus is possible only on the basis of a microscopic examination of the resulting culture.
Laboratory diagnosis of superficial candidiasis
For laboratory testing for yeast-like fungi, fresh material is required. For microscopic examination, depending on the clinical manifestations and localization of the lesions, skin flakes, scrapings from the nails, a drop of pus from under the nail fold, whitish deposits from the affected areas of the oral mucosa and external genitalia, vaginal walls, scrapings from the mucous membrane can be taken. membranes of the urethra, as well as washings from the red border of the lips, affected areas of the skin of large and small folds.
Depending on the location of the lesion and the nature of the clinical manifestations, the material for research is taken with a cotton swab, scalpel, loop, etc. Skin and nail scales, scraps of the epidermis and scrapings of the mucous membrane are pre-treated with 30% KOH. Pathological material is examined in unstained or stained preparations.
In the first case, the material is mixed with an equal amount of alcohol and glycerin. When stained by Gram, yeast cells and pseudomycelium appear dark purple, by Ziehl-Neelsen - blue, and by Romanovsky-Giemsa - pink-violet. In this case, a distinctive feature of a yeast cell is budding - the discovery of an “hourglass” figure. Taking material from the mucous membrane of the oral cavity, genitals, from the skin of the red border of the lips, from the corners of the mouth, from the skin of large and small folds is carried out with a sterile swab. After taking the material, the swab is placed in another sterile tube with liquid wort. The test tube with the swab is sent to the microbiology laboratory. Isolation of a pure culture of yeast-like fungi of the genus Candida is carried out according to generally accepted microbiological methods.
First appointment
At the appointment, the mycologist conducts an examination and also prescribes a comprehensive examination. Laboratory diagnostics
The most effective methods for diagnosing skin mycoses are various laboratory tests that can identify the pathogen and help in selecting a treatment regimen. To identify the causative agent of mycosis, the following laboratory tests are prescribed:
- histological analysis;
- bacteriological culture;
- immunological research;
- PCR diagnostics;
- cultural examination;
- microbiological research.
Microbiological diagnostics helps to detect the fungus and determine its genus and species. Microbiological diagnosis is the most common and simplest method for detecting mycosis in the blood and skin. To identify an accurate diagnosis, you should know how to correctly collect the material that is necessary for the study. Affected hair should be collected with tweezers. If the skin is infected, the skin from the damaged area should be scraped for microscopy. All collected material is placed in a 30% potassium hydroxide solution and then on a glass slide. Microbiological diagnostics can reveal exactly where the fungus is located (inside or outside the hair, skin) and its size.
To prevent an erroneous diagnosis of mycosis, material should be collected correctly and competently for microbiological examination.
In medicine, there are the following microbiological diagnostic methods:
- Microscopy using native or unstained preparations. To do this, the material is clarified using 10-30% solutions of potassium or sodium hydroxide. Then the processed material is placed on a laboratory glass, into which a little glycerin has previously been dripped. The top is covered with a glass plate and analysis is carried out.
- Microscopy of stained preparations is carried out in several ways that identify bacteria, differentiate different bacteria and identify different fungi.
Bacteriological culture
Bacteriological culture is one of the most effective methods for diagnosis.
Collecting a bacteriological culture on a nutrient medium is an accurate way to diagnose mycosis. Taking into account the appearance and characteristics of the grown fungal colony, the dermatologist determines the type of pathogen that caused mycosis. The only downside to the survey is that it takes a long time to grow a colony. On average, it takes about 3 weeks to find out the pathogen strain. In some cases, the method does not bring the expected results.
PCR diagnostics
The PCR diagnostic method involves identifying the causative agent of mycosis using a polymerase chain reaction. During the examination, the sensitivity of hybridization increases, which increases the content of viral DNA in the test material. This examination method is new and requires several tests from the patient. It is believed that this type of diagnosis is quite expensive, but gives accurate results.
Culture examination
Cultural diagnostic measures are recommended at the final stage of diagnosis. The method consists of obtaining a culture of the fungus, which is then sent for examination using a microscope. The resulting material is placed on an artificially created nutrient medium and the type of pathogen, appearance, and size are identified. After which special treatment is indicated, which is aimed at combating a specific type of mycosis pathogen.
Precision diagnosis of invasive mycoses not easy. This is explained not only by difficulties in obtaining a culture of fungi, but also in interpreting research results, since fungi, both yeast and filamentous, can colonize mucous membranes and contaminate the studied samples. In this regard, the diagnosis of invasive mycoses is based on an integrated approach, including not only the results of mycological (cultural) and serological (determination of fungal antigen) studies, but also clinical symptoms of fungal infection, data from auxiliary research methods (computer or magnetic resonance imaging, ultrasound ).
European-American Cooperation Group for the study of invasive mycoses Criteria for diagnosing invasive mycoses have been developed in immunocompromised patients. They were presented in 2001 at the International Conference on Antimicrobials and Chemotherapy (ICAAC, Chicago), and in 2002 in print. Criteria for proven, probable and possible invasive mycosis have been defined, which are recommended for use in clinical and epidemiological studies
Proven invasive mycosis caused by filamentous fungi: detection of fungal mycelium in biopsies or aspirates during histological or cytological examination or isolation of a culture from samples obtained under aseptic conditions from a normally sterile lesion, which, according to the results of clinical and radiological studies, is associated with infection, with the exception of studies of urine and mucous membranes.
Proven invasive mycosis caused by yeast fungi: detection of yeast cells (fungi of the genus Candida can form pseudomycelium or true mycelium) in biopsies or aspirates, with the exception of samples from mucous membranes, or isolation of culture from samples obtained under aseptic conditions from a normally sterile lesion, which according to the results of clinical and radiological examination associated with infection, with the exception of urine, samples from the sinuses and mucous membranes, or the detection by microscopy and specific staining (in a drop of India ink, mucicarmine stain) of yeast cells or a positive antigen of Cryptococcus spp. in the cerebrospinal fluid.
Fungemia caused by filamentous fungi: isolation of blood culture of fungi, with the exception of Aspergillus spp. and Penicillium spp., including Penicillium marneffei, in combination with clinical symptoms of an infectious process compatible with the isolated pathogen.
Fungemia caused by yeast fungi: blood culture isolation of Candida or other yeast fungi from patients with clinical signs of infection associated with this pathogen.
Complex of diagnostic studies for invasive mycoses
| Biomaterial under study | Indications, media used, meaning |
| Blood |
Indications:
persistent fever (4-5 days or more) during therapy with broad-spectrum antibiotics; second “wave” of fever during antibiotic therapy Collecting blood from a vein into vials for aerobic bacteria* or into a selective medium for fungi, repeated (2-3 times a day with an interval of 1 hour) Diagnostic significance: isolation of yeast fungi, careful interpretation when isolating filamentous fungi, with the exception of Fusarium spp. |
| Venous catheter |
Indications:
isolation of yeast fungi from the blood The central or peripheral venous catheter is removed in all cases of yeast isolation from the blood For mycological research, an aseptically removed distal section of the catheter 5-6 cm long is used. The study is carried out semi-quantitatively (Maki method) or quantitative method on Sabouraud’s medium Diagnostic significance:
|
| Upper respiratory tract discharge, sputum, washings from the trachea, bronchi, bronchoalveolar lavage fluid |
Indications:
suspicion of mycoses caused by filamentous fungi or Cryptococcus neoformans; prolonged fever during broad-spectrum antibiotic therapy and neutropenia Microscopy of samples with calcofluor white (detection of mycelium or pseudomycelium); sowing on Sabouraud's medium; determination of Aspergillus antigen in bronchoalveolar lavage fluid in the presence of lesions in the lungs characteristic of invasive aspergillosis Diagnostic significance: isolation of filamentous fungi or Cryptococcus neoformans |
| Cerebrospinal fluid |
Indications:
symptoms of meningitis; detection of a lesion(s) in the brain using computed tomography or magnetic resonance imaging; "brain" symptoms due to fever and neutropenia Microscopy with calcofluor white, in a drop of ink; determination of Aspergillus, Cryptococcus antigen; sowing on Sabouraud Wednesday Diagnostic significance:
|
| Biopsies, aspirates, peritoneal fluid, pleural fluid |
Indications:
clinical and/or radiological signs of invasive mycosis; fever during therapy with broad-spectrum antibiotics. Microscopy with calcofluor white, culture on Sabouraud's medium Diagnostic significance:
|
Possible invasive mycosis diagnosed based on the combination of the following criteria:
one sign from the category of microbiological criteria;
one sign from the category of “significant” or two from the group of “less significant” clinical symptoms of the infectious process.
Possible invasive mycosis diagnosed based on a combination of the following criteria:
the presence of at least one risk factor inducing the development of invasive mycosis;
one sign from the category of microbiological criteria or one sign from the category of “significant” (two from the group of “less significant”) clinical symptoms of the infectious process.
The concept " possible invasive mycosis» It is not recommended for use in clinical trials studying the effectiveness of antifungal drugs. You can use this term when analyzing empirical antifungal therapy, epidemiological studies, and studying pharmacoeconomics.
At mycological research sterile aspirates or biopsies take into account not only the isolation of fungal cultures, but also the detection of mycelium or pseudomycelium by microscopy. In histological preparations, Aspergillus is difficult to differentiate from Fusarium spp., Sceclosporium apiospermum and some other filamentous fungi. For differential diagnosis, an immunohistochemical study with antibodies to Aspergillus should be performed.
Isolation of yeast fungi from the blood in at least one study belongs to the category of “proven” invasive mycosis and is an absolute indication for the prescription of systemic antimycotics in patients with neutropenia. The frequency of detection of yeast fungi from the blood is low, even with disseminated candidiasis it is 35-50%.
Carrying out repeated blood cultures increases the likelihood of obtaining positive results.
Other interpretation results in case of detection of filamentous fungi in the blood. A high frequency of isolation of filamentous fungi is characteristic of Fusarium spp. and amounts to 40-60%. Aspergillus is detected extremely rarely, in most cases it is considered as contamination, with the exception of Aspergillus terreus.
Selection Aspergillus terreus from the blood of patients with hemoblastoses may indicate true aspergillemia, and in the presence of clinical symptoms of infection, it is the basis for prescribing antimycotics.
Criteria for invasive mycosis
| Index | Criteria |
| Factors inducing the occurrence of invasive mycosis (macroorganism) | Neutropenia (< 0,5*109/л в течение 10 дней)
Persistent fever for more than 96 hours during broad-spectrum antibiotic therapy Body temperature above 38 °C or below 36 °C and any of the following predisposing signs: prolonged neutropenia (more than 10 days) during the previous 60 days, intensive immunosuppressive therapy within the last 30 days, proven or probable invasive mycosis in the previous period neutropenia or AIDS Presence of symptoms of GVHD, primarily cases of severe course (II degree) or extensive course of chronic disease Long-term (more than 3 weeks) use of glucocorticoids within the last 60 days |
| Microbiological signs | Culture isolation of filamentous fungi (including Aspergillus spp., Fusaruim spp., Sceclosporium spp. and zygomycetes) and Cryptococcus neqformans from sputum or bronchoalveolar lavage fluid Positive results of cultural or cytological examination (direct microscopy) for the detection of filamentous fungi from aspirates of the paranasal sinuses Detection of filamentous fungi or Cryptococcus neoformans by cytology/direct microscopy from sputum or bronchoalveolar lavage fluid Positive Aspergillus antigen in bronchoalveolar lavage fluid, cerebrospinal fluid and blood samples (at least two) Positive cryptococcal antigen in blood samples Detection of fungal elements by cytological examination or direct microscopy in samples of normally sterile fluids (for example, Cryptococcus spp. in cerebrospinal fluid) Two positive results of studies on the detection of yeast cultures in urine in the absence of a urinary catheter Candida crystals in urine without a urinary catheter Isolation of Candida spp. from blood cultures |
|
Clinical signs
Lower respiratory tract |
Must be associated with the locus from which samples are taken for microbiological research Any of the following types of new pulmonary infiltrates according to CT: halo sign, crescent sign, cavity with areas of consolidation* Symptoms of lower respiratory tract infection (cough, chest pain, hemoptysis, dyspnea), pleural friction rub, any new infiltration not included in the signs of high significance; pleural effusion |
| Upper respiratory tract Signs of high significance Signs of lesser significance |
Radiological signs of invasive infection in the nasal sinuses (wall erosion or spread of infection to adjacent structures, extensive destruction of the skull bones) Runny nose, nasal congestion, nasal ulceration, epistaxis, periorbital edema, pain in the upper jaw, black necrotic ulceration or perforation of the hard palate |
| central nervous system Signs of high significance Signs of lesser significance |
Radiological signs of suspected CNS infection (mastoiditis or other parameningeal focus, extradural empyema, multiple lesions in the substance of the brain or spinal cord) Focal neurological symptoms and signs, including focal seizures, hemiparesis; disorders of consciousness, meningeal symptoms, disturbances in the biochemical composition of the cerebrospinal fluid and its cellular composition (in the absence of other pathogens, according to culture and microscopy, in the absence of tumor cells) |
At detection in blood or other sterile biosubstrates of yeast fungi, it is necessary to carry out identification to the species and determine sensitivity to antifungal drugs; when isolating filamentous (mold) fungi, only identification to the species, sensitivity is not determined.
In clinical practice The sensitivity of filamentous fungi is not studied due to imperfect standards for determining the sensitivity of such fungi to antimycotics. Moreover, only one study demonstrated a correlation between the susceptibility of Aspergillus spp. and the results of treatment of invasive aspergillosis in patients with hematological malignancies. None of the subsequent studies found similar results.
Recently, isolated reports have begun to appear about the formation of acquired resistance of A. fumigatus fungi to itraconazole and voriconazole.
Identification of mushrooms to species, especially those obtained from sterile loci, is necessary primarily for choosing an antimycotic and conducting adequate antifungal therapy. Thus, Candida krusei is resistant to fluconazole and less sensitive than other yeast species to amphotericin B; Aspergillus terreus, Scedosporium apiospermum (Pseudallescheria boydii), Trichosporon beigelii, Scopulariopsis spp. resistant to amphotericin B; Mucorales are resistant to itraconazole, voriconazole, Candida glabrata exhibits dose-dependent sensitivity to fluconazole, and when this type of fungus is isolated, even sensitive strains, the dose of fluconazole should be increased (adults are prescribed 800 mg instead of 400 mg); Candida lusitaniae is resistant to amphotericin B.
Identification of mushrooms to species is also important for conducting epidemiological analysis in a hospital - identifying the causative agents of outbreaks of infection and, if possible, the source of infection. Outbreaks of infection caused by such rare fungi as C. lusitaniae, C. krusei, C. lipolytica have been described.
Based mushroom species identification Invasive mycosis or fungal colonization of the mucous membranes can be assumed. For example, Aspergillus niger is significantly less likely than Aspergillus fumigatus to cause invasive aspergillosis in patients with acute leukemia. Isolation of Aspergillus niger from bronchoalveolar lavage fluid is most often regarded as colonization of the respiratory tract, and from sputum as contamination from the air and requires additional research when confirming the diagnosis of invasive aspergillosis.
Based secretions of filamentous fungi from sputum, bronchoalveolar fluid, and aspirate of the paranasal sinuses, one can only assume invasive mycosis, without including it in the “proven” category. However, the detection of Aspergillus in sputum, especially Aspergillus fumigatus or Aspergillus flavus, in neutropenic patients receiving allogeneic bone marrow should always be taken into account. This requires repeat mycological examination and computed tomography of the lungs. Thus, with neutropenia, the likelihood of detecting invasive aspergillosis in the case of a positive culture of Aspergillus spp. in sputum is 80%.
Selection Cryptococcus neoformans in immunocompromised patients from the respiratory tract (washes, lavage) is diagnostically significant. If the identification of yeast fungi from fluids obtained from the respiratory tract (tracheal, bronchial lavages, bronchoalveolar lavage) of immunocompromised patients is not required research, then screening to identify Cryptococcus neoformans from these samples is necessary.
Detection of candida in urine in patients with neutropenia and fever, it is usually considered a manifestation of disseminated candidal infection.
In a timely manner diagnostics invasive successfully use a commercial test to detect the circulation of a specific antigen of Aspergillus spp. galactomann (polysaccharide water-soluble component of the cell wall of the fungus).
Galactomann can be determined by two methods: the latex agglutination method (Pastorex Aspergillus, BioRAD) and the enzyme immunoassay method (Platelia Aspergillus, BioRAD).
Advantage enzyme immunoassay method is a lower sensitivity threshold for determining the level of galactomann in the blood - 1 ng/ml or less, and using latex agglutination - 15 ng/ml. The determination of galactomann in the blood (at least 2 samples), cerebrospinal fluid, and bronchoalveolar lavage is of diagnostic value. The sensitivity of the enzyme immunoassay method is about 90%, the specificity is 90-99%, in recipients of allogeneic bone marrow these indicators are lower and are equal to 60-70% and 80-90%, respectively, due to the prophylactic use of antifungal drugs (antimycotics reduce the threshold level of galactomann).
In 40% of cases, detection galactomann in the blood is ahead of the manifestations of invasive aspergillosis, determined by computer examination of the lungs, and in 70% it is ahead of the clinical symptoms of infection.
Diagnostic value of antigen detection test Aspergillus is the case if the study is carried out repeatedly. Determination of Aspergillus antigen in the blood should be carried out during fever during treatment with broad-spectrum antibiotics in patients with neutropenia 2 times a week; for pneumonia that occurs or persists during antibacterial therapy; when lesions are detected in the lung tissue (computed tomography).
Diseases caused by fungi or mycoses are a common problem. There are an incredible number of pathogens that cause mycoses.
Every year, scientists discover and describe new species of fungi. Despite this, the diagnosis and treatment of mycoses is a long-established and clear mechanism.
Types of fungal diseases
In humans, most fungi affect mucous membranes and skin.
Diseases in which fungi are the cause of the disease include:
- ringworm
- candidiasis
- onychomycosis
- variegated or pityriasis versicolor
- lichen black
- seborrhea
- aspergillosis
Methods for diagnosing mycoses
One of the most popular methods is microbiological diagnosis of mycoses.
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Modern diagnostic methods make it possible to accurately determine which fungus was the cause of the disease. In the future, this makes it possible to choose the optimal course of treatment. At the moment, there are three main methods for laboratory diagnosis of mycoses.
These include:
- microscopic
- cultural
- serological
Each method has its own advantages. Cultural diagnosis of mycoses allows you to determine the type of fungus. In this case, it is possible to assess the sensitivity of colonies to various drugs.
This method will allow you to select an effective drug. This method requires a lot of time for sowing and growing colonies.
Microscopic and serological methods for diagnosing mycoses require less time. When using them, the type of pathogen is also determined, but it is impossible to check its sensitivity to the drugs. In some cases, it is possible to use a luminescent diagnostic method. This method is less common due to its complexity.
The luminescent method can only be used when hair is affected by fungi. The method is ineffective for diagnosis in the early stages. This is due to the fact that the glow effect will only appear if the hair is heavily damaged by fungus.
Diagnosis of mycosis of the foot
Mycosis of the foot is one of the most common dermatomycosis.
This term is commonly understood as a fungal infection of the skin of the foot and nails.
Remember! The disease has a relapsing course.
When diagnosing mycosis of the foot, it is necessary to differentiate it from a number of other diseases. Diagnosis of mycosis of the foot is based on clinical manifestations and microscopic examination. It is possible to use the cultural method.
Treatment of mycoses
Antifungal drugs of local and systemic action play a leading role in the treatment of mycoses.
Treatment with local antimycotics is aimed directly at the source of the disease. At the same time, the negative impact on the body as a whole is minimal.
Systemic antimycotic drugs are prescribed if:
- local antifungal drugs are ineffective
- the disease is systemic in nature
Desensitizing and antihistamine drugs are prescribed when mycoses are accompanied by an inflammatory process or allergic reactions. If a secondary infection is associated with mycoses, antibacterial drugs may be prescribed.
It is important to begin treatment of fungal diseases in the early stages of the disease. If the process is old, treatment may take longer.
When the first symptoms appear, immediately seek help from our doctor.
According to scientists, 70% of the world's population has symptoms of mycosis of the feet. This disease affects the interdigital folds and the skin on the soles. The cause of the disease is a fungus that was initially found only in limited areas of southeast Asia and Africa. The First World War, causing mass migration of people and deteriorating sanitary conditions, led to the spread of the disease throughout the world.
What causes mycosis of the feet
The main causative agent of the disease is Trichophyton rubrum. Infection can be caused by T. mentagrophytes and Epidermophyton floccosum. Fungi of the genus Candida and mold microorganisms can become pathogenic microbes much less frequently.
The most significant risk factors for the disease:
- diabetes;
- immunodeficiency state (AIDS);
- flat feet;
- atherosclerosis of peripheral arteries;
- varicose veins of the lower extremities.
External conditions conducive to the development of infection:
- closed non-absorbent shoes;
- foot injuries (calluses, abrasions);
- playing sports.
Symptoms of athlete's foot most often occur in adult men. Children rarely get sick.
Symptoms of mycosis of the feet
As the disease develops, peeling and dry skin, itching and burning appear, especially in the spaces between the fingers, and the appearance of painful cracks under the fingers. Sometimes the first symptoms of mycosis of the foot are blisters that burst with the formation of erosions. Often the disease occurs in an erased form, manifested only by slight peeling, reminiscent of flour, in the folds between the fingers.
There are 4 clinical forms of the disease.
The interdigital, or intertriginous, variant is the most common. The skin between the fingers turns red, cracks, the surface layer becomes wet and peels. These signs extend to the sole and are accompanied by severe itching and burning. Bacterial inflammation is often associated.
The squamous-hyperkeratotic variant is associated with severe thickening and cracking of the skin. The sole turns red and peels. Deep, painful cracks appear in the heel area; itching is usually uncharacteristic. This is often a bilateral lesion and is also called “moccasin foot.”
The dyshidrotic variant is accompanied by the appearance of multiple small itchy, painful blisters. They merge with each other, forming large bubbles. The covers of the blisters burst, revealing a shiny, vulnerable, painful surface - erosion. External manifestations resemble eczema.
Microbial inflammation is often associated with enlarged inguinal lymph nodes, fever, pain in the leg, nausea, headache and other signs of intoxication. With the dyshidrotic form, an allergy to fungi often occurs - mycotic eczema. It is accompanied by rashes on areas of the body that are not infected with the fungus, for example, on the hands.
The erased version usually goes unnoticed. It is accompanied by slight peeling of the skin between the big and index and/or ring and little fingers on the foot. There is no itching.
Signs of mycosis of the feet
Different types of mycosis of the feet can be independent diseases or occur as part of a general fungal infection of the body. Sometimes the sign “two feet - one hand” occurs with the involvement of these organs. Onychomycosis, a fungal destruction of the nail, may occur. Sometimes the inguinal folds are affected at the same time.
The main symptoms and treatment of mycosis of the foot are presented in the photo:
Peeling skin
Dry and cracked skin
Bubbles and erosions
Diagnostics
An experienced dermatologist can recognize the different types of mycosis of the feet during the first examination. However, microscopic examination is necessary to confirm the diagnosis. For it, scales from the lesion are used, scraped off with a spatula and treated with an alkali solution. The resulting material is examined under a microscope and pathogens are detected.
Direct microscopy is fast, cheap and easy to perform, but cannot determine which type of fungus is causing the disease. Therefore, the material is inoculated on a nutrient medium, followed by a cultural examination of the resulting material. However, it is possible to obtain a culture of the fungus after detecting it under a microscope only in 20–6% of cases.
Types of treatment for mycosis of the feet
Drugs for the treatment of fungal diseases should be prescribed by a dermatologist. Usually, treatment of mycosis of the foot is carried out using external means.
One of the effective drugs for this disease is clotrimazole. In our store you can buy it at a low cost. A medicine in the form of a lotion, Clotrimazole for nails and skin, suppresses the proliferation of fungi in the thickness of the stratum corneum of the epithelium. If the interdigital folds are affected, the lotion is applied daily to clean, dry skin of the feet for a week, longer if necessary.
In case of severe keratinization and cracking of the skin, it is first necessary to remove dead skin deposits. This requires the use of exfoliating medications. For example, salicylic ointment, creams with lactic acid or urea are prescribed. After removing horny deposits, the lotion is used 1 – 2 times a day.
In the dyshidrotic variant, the first step is to reduce weeping. For this, lotions with tannin or boric acid are used. In severe cases, glucocorticoids are added to treatment. Then apply Clotrimazole lotion according to the usual regimen.
If the foot is worn out, treat it with lotion once a day for 7-10 days, but the duration of the course is individual and determined by the doctor.
Systemic therapy
Long-term or recurrent athlete's foot may require oral antifungal medications. They pass from the gastrointestinal tract into the bloodstream and then into the skin, where they destroy fungi. Three main drugs are used:
- fluconazole;
- itraconazole;
- terbinafine
The duration of taking these drugs is at least a month. Their price is quite high. Therefore, preventing mycosis of the foot is always easier and more profitable than curing it.
Systemic drugs are especially often prescribed if the fungus has affected not only the skin, but also the nails. In this case, the drugs accumulate in the growing part of the nail plate, and a healthy nail gradually grows back. To improve the effect, the nail can be completely removed surgically, after which it is restored without fungus.
A combination of nail removal and systemic and local antifungal therapy is often necessary in elderly patients. In this group of patients, nails often grow slowly, blood circulation in the feet is impaired, so a large dose of drugs and a long course of treatment are required to achieve an effect.
Treatment with folk remedies
Using only traditional medicine recipes will not help get rid of the fungus. However, such an addition to conventional therapy shortens the course of treatment and speeds up recovery.
It is useful to take warm foot baths every evening for 10 minutes, then pat your feet thoroughly with a towel, especially between the toes, and apply Clotrimazole medicinal lotion for nails and skin. Useful bath ingredients that relieve inflammation and reduce itching:
- herb celandine and St. John's wort;
- burdock roots;
- wormwood grass;
- eucalyptus leaves;
- fir needles;
- fresh grounds from brewed ground coffee;
- salt;
- a mixture of grated laundry soap, baking soda, potassium permanganate and mustard powder.
The affected areas can be lubricated with birch tar or a self-prepared ointment made from 100 grams of butter mixed with a crushed head of garlic. Propolis, which can be bandaged to sore nails, is also useful.
It is useful to make compresses from natural remedies. First, they are left for 1 to 2 hours, and if tolerated, overnight. The following ingredients are used:
- pumpkin pulp;
- crushed black radish seeds;
- peppermint, ground with salt;
- burdock or rowan leaves, slightly softened with a rolling pin.
It is effective to lubricate the affected areas with the juices of some plants and other natural remedies:
- alcohol solution of propolis;
- onion or garlic juice;
- celandine juice;
- tea tree oil.
Disease prevention
In order to avoid mycosis or prevent its relapse, simple but constant prevention is needed:
- in summer, wear breathable shoes made of natural material;
- when visiting swimming pools, baths, public showers, wear individual rubber slippers;
- do not wear someone else’s shoes, for example, when visiting;
- use only your own hygiene equipment - scissors, pumice stone, nail file.
To avoid re-infection, the insoles and inner surfaces of shoes should be regularly treated with disinfectants. A well-known folk recipe is a solution of vinegar essence, but it has a sharp, unpleasant odor.
Doctors recommend using the drug Mikospray, which has not only an antifungal but also an antibacterial effect. Mycospray is great not only for treating shoes, but also for applying to feet before visiting public places to protect feet.
Residents of Moscow and the regions can purchase drugs for the treatment of mycosis of the foot and for its prevention in our online store. They have proven effectiveness and safety. Their use is recommended for all people who do not want to become infected with foot fungus or quickly get rid of it.
