Ph.D. T.L. Lapina, academician of RAMS, professor V.T. Ivashkin
MMA named after I.M. Sechenova
The value of fungal infection in gastroenterology is either overestimated, or vice versa, does not find a proper assessment. Often there is a clear overdiagnosis. For example, on the basis of the presence of Candida mushrooms in the culture of a smear from the oral mucosa in a person without signs of stomatitis, or in the analysis of feces “for dysbiosis” of a patient with irritable bowel syndrome, a diagnosis of candidiasis or even “systemic mycosis” is established.
At the same time, it is completely ignored that the fungus is a human commensal and is widespread in the environment (such as Candida, Aspergillus). Therefore, the isolation of, say, representatives of Candida from the surface of the skin, oral cavity, from sputum, urine and feces should be interpreted with caution.
Always keep in mind that many fungi do not exhibit pathogenic properties if the host organism is not weakened. Violations of the anatomical, physiological and immunological mechanisms of the body’s defense create the conditions for the development of the infectious process caused by its own, under normal conditions, non-pathogenic microflora or saprophytic microorganisms from the environment.
Conditions for the development of opportunistic infections include: treatment with corticosteroids, immunosuppressants, antimetabolites, antibiotics, AIDS and other immunodeficiency conditions, serious metabolic disorders (e.g., with diabetes mellitus, renal failure), neoplasms and antitumor therapy.
Fungal infection, including the gastrointestinal tract, developing against the background of a serious illness, must be recognized in time and adequately treated, since this infection can have a negative effect on the prognosis of the underlying disease.
A correctly recognized fungal infection of the gastrointestinal tract often provides the primary diagnosis. So, candidiasis of the oral cavity and esophagus is one of the “calling cards” of AIDS. One of the important gastroenterological aspects of the problem under consideration is that fungal infection can be a complication of enteral and especially parenteral nutrition.
Most often, in patients with suppressed immunity there is an infection with Cand> albicans, less often with other representatives of the genus Candida.
Candida stomatitis is characterized by a white coating that rises slightly above the mucous membrane of the oral cavity and resembles clotted milk or cottage cheese. When plaque is removed, a hyperemic surface is exposed, which may bleed slightly (pseudomembranous form). With an atrophic form, the lesions have the appearance of erythema. Symptoms include dryness, burning, a frequent decrease in taste sensitivity.
Candidiasis stomatitis is widespread among AIDS patients (one of the most common manifestations of the disease), as well as the use of antibiotics, corticosteroids and antitumor agents.
Fungal esophagitis is most often candidal. They develop in immunodeficiency states, antibiotic therapy, often in patients with diabetes mellitus (a high concentration of glucose in saliva is favorable for the growth of fungi), in people of old age or with impaired trophological status. Fungal esophagitis is also found with achalasia of the cardia, other motor disorders, for example, in the framework of scleroderma, and with esophageal stenosis.
Clinically, fungal esophagitis is manifested by dysphagia and odnophagia (painful swallowing). In severe cases, specific esophagitis can be complicated by bleeding, perforation, stricture of the esophagus or the development of candidiasis sepsis. An endoscopic examination determines yellow-white relief overlay on the hyperemic mucous membrane of the esophagus.
X-ray examination can reveal multiple filling defects of various sizes. The diagnosis is confirmed by microscopic examination of smears obtained by esophagoscopy.
Complaints of dysphagia and discomfort behind the sternum in an AIDS patient are the basis for a wide differential diagnosis, since damage to the esophagus in these patients can be caused by viruses (herpes simplex, cytomegalovirus), and the development of Kaposi’s sarcoma, and other reasons. However, the diagnosis of candidal esophagitis cannot be called complicated.
The presence of fungal stomatitis in an HIV-infected patient with dysphagia is likely to indicate the correct etiology of esophagitis, and endoscopy with microbiological or histological examination clearly establishes the diagnosis in 95.5% of cases (I. McGowan, I.V.D. Weller, 1998).
With the suppression of the immune system and a general weakening of the body, development is possible fungal gastritis, the most common causative agent of which are representatives of the genus Candida, Histoplasma, Mucor.
Candidiasis with damage to the small and large intestine, as a cause of diarrhea, is not as common as it might seem at first glance. Diarrhea is one of the most common symptoms of immunodeficiency, and not only infectious agents become its cause. However, the role of fungal infection (including Candida), as the causes of diarrhea, is small.
Thus, in AIDS, the causative agents of the infectious process in the small and large intestine, accompanied by diarrhea, are, first of all, the simplest ones - Cryptosporidium, Microsporidium (Enterocytozoon beineusi), Isospora belli, Giardia lamblia. Of the viruses associated with AIDS with the development of diarrhea syndrome, cytomegalovirus and herpes simplex virus should be called, and Salmonella, Shigella, Campylobacter spp.
It is important to pay attention to a well-differentiated nosological unit - pseudomembranous colitis. This is an acute inflammatory bowel disease associated with antibiotic therapy. Its clinical presentation varies from short-term diarrhea to severe form with fever, dehydration and complications. Cases of this disease with uremia, after cytostatic therapy, are described.
Colonoscopy on the mucous membrane reveals fibrinoid overlays, due to which the disease got its name. Despite the superficial resemblance to candidiasis (the onset of the disease is provoked by antibiotics, white deposits appear on the mucous membrane), pseudomembranous colitis has nothing to do with this fungal infection.
The causative agent of colitis associated with antibiotics (synonymous with pseudomembranous colitis) has been established. This is Clostridium difficile - a gram-positive anaerobic. Antibiotic therapy, suppressing its own microflora, creates conditions for the propagation of C. difficile and the manifestation of its pathogenic properties.
The diagnosis is established based on the identification of the pathogen in the feces or by detection of the C. difficile toxin. This retreat, devoted to pseudomebranous colitis, once again emphasizes the need for an adequate assessment of the clinical picture, instrumental examination data and laboratory tests. The diagnosis of fungal infection, including candidiasis, should be based on the fullest possible information.
Causes and symptoms of intestinal candidiasis
An intestinal fungus develops in people with impaired immunity, therefore it is more common in women than in men, and this is due, for example, to a decrease in immunity during menstruation.
Fungi growing on the walls of the intestine need sources of organic carbon, as they are not able to create carbohydrates from carbon dioxide and water.
The simplest source of carbohydrates are sugars, therefore, as causes of intestinal fungus The following factors are listed:
- the use of excessive amounts of sugar - despite the fact that they are the best source of carbohydrates, sugars affect the development of intestinal candidiasis,
- swallowing food without first thorough grinding - poor chewing of fruits and products prevents their absorption in the small intestine.
Other factors causing intestinal fungus development:
- the use of drugs that reduce the acidity of the stomach,
- antibiotic therapy
- imbalance in the normal composition of the flora - the yeast release toxins, which leads to a weakening of the immune system, and, therefore, facilitates the development of the fungus.
Symptoms of intestinal candidiasis non-specific and do not always immediately indicate the development of the disease. These include:
- bloating and gas, which is formed as a result of alcoholic fermentation of yeast,
- rumbling and gurgling in the intestines,
- abdominal pain of unknown origin, localized inside the left and right lower pelvis,
- loose stools from the onset of the disease, and then less and less, up to watery diarrhea,
- diarrhea that occurs after taking a certain group of products,
- desires for stools that occur immediately after bowel movements.
Bowel candidiasis treatment
An intestinal fungus has no pharmacological treatment with drugs and antibiotics. Gastrointestinal fungus can be treated with an appropriate diet. It allows you to restore homeostasis of the composition of the microflora of the colon. The antifungal diet is based on healthy and wholesome foods.
It is recommended that the patient eat:
- whole wheat bread (in moderation),
- lean meat and sausages, fish and eggs,
- tuberous vegetables (raw and boiled): spinach, tomatoes, cucumbers, legumes (fruits),
- sauerkraut, onions, garlic, garden herbs,
- sour fruits (including sugarless stewed fruit).
Diet for intestinal candidiasis should exclude foods containing simple and complex carbohydrates. The patient should avoid:
- any kind of sugar and all sugar-based dishes (cakes, pies, cookies, bread, yeast),
- sweet fruits (peaches, plums, grapes, oranges),
- sweet fruit juices
- pasta and white flour products.
In addition, appropriate probiotics or protective agents may also be given.
The most common fungal lesions of the gastrointestinal tract - candidiasis of the oral cavity and esophagus - have quite characteristic signs. For a correct diagnosis, obtaining a pathogen culture must be confirmed by characteristic clinical symptoms, with the exception of another etiology, as well as histological signs of tissue invasion.
In the case of systemic candidiasis, the diagnosis helps to plant the fungus from blood, cerebrospinal fluid or from tissues, for example, liver biopsy, which will clarify the clinical signs - septicemia, meningitis or liver damage.
Much less significant in gastroenterology are Cryptococcus and Histoplasma. As a rule, involvement in the pathological process in these fungal infections of the gastrointestinal tract and liver occurs in patients with immunodeficiency with a disseminated form of the disease.
Histoplasma capsulatum with hematogenous spread from the lungs affects the liver and spleen with the phenomena of hepato- and splenomegaly, and damage to the gastrointestinal tract is accompanied by ulceration (especially often of the oral cavity).
In AIDS, Cryptococcus neoformans and Histoplasma spp. with disseminated cryptococcosis and histoplasmosis, the liver is affected by the type of granulomatous hepatitis. Clinically and biochemically, there is a cholestasis syndrome. To establish an accurate diagnosis, a liver biopsy is required, in which fungal tissue invasion will be proven.
Modern antifungal agents are a very impressive arsenal.
Fluconazole (a water-soluble triazole) highly selectively inhibits the fungal cytochrome P450, blocks the synthesis of sterols in fungal cells. Today there is a domestic fluconazole - Flucostat. It is almost completely absorbed in the gastrointestinal tract, which allows you to quickly achieve adequate concentrations in serum. It is used for candidiasis and cryptococcosis.
In AIDS, for the treatment of cryptococcosis after a preliminary course of amphotericin B (without fluorocytosine or in combination with it, which is preferable), fluconazole is prescribed 200 mg per day.
Ketoconazole (an imidazole derivative) has a wide spectrum of antifungal activity, however, unlike fluconazole, it can cause a temporary blockade in the synthesis of testosterone and cortisol.
Fluorocytosine is incorporated into the cells of the fungus, where it is converted to 5-fluorouracil and inhibits thymidylate synthetase. Typically, the drug is used to treat candidiasis, cryptococcosis, chromomycosis.
Amphotericin B acts on the sterols of the fungal membrane, disrupts its barrier function, which leads to the lysis of fungi. Indications for its use are systemic mycoses - candidiasis, aspergillosis, histoplasmosis and others.
Given the severity of the diseases against which opportunistic infections are possible, antifungal therapy often requires a combination of drugs, repeated courses, or supportive treatment. As an example, possible treatment options for candidiasis of the gastrointestinal tract in AIDS patients are presented in the table.
I. Oropharyngeal candidiasis.
- Oral candidiasis in newborns.
- Pseudomembranous candidiasis.
- Atrophic candidiasis of the oral cavity (more often in the elderly).
- Erythematous candidiasis (new form).
- Median rhomboid glossitis.
- Leukoplakia associated with candidiasis.
- Angular candidal cheilitis.
- Candidiasis gingivitis (rarely isolated in isolation).
II. Candidiasis esophagitis.
III. Candidiasis of the stomach.
- Erosive-fibrinous gastritis (diffuse).
- Secondary candidiasis on the background of peptic ulcer.
- IV. Bowel candidiasis.
V. Candidiasis proctosigmoiditis.
VI. Perianal candidiasis.
VII. Secretory diarrhea associated with candidiasis.
|Figure 3. Candidiasis glossitis. Typical white deposits and erosion on inflamed infiltrated mucosa|
Among all localizations of candidiasis of the digestive tract, oropharyngeal takes the 1st place.
Hippocrates mentioned oral candidiasis and was first described by the surgeon Langenberk in 1839.
Candidiasis stomatitis in newborns is a common disease. In the first days after birth, the mucous membranes of the baby are resistant to fungi.
In the future, insufficient secretion of IgA and a gradual decrease in antimicrobial immunity transmitted from the mother lead to high morbidity. Pathognomonic syndrome - white curdled deposits on the oral mucosa, the so-called "thrush."
Candidiasis is also associated with wearing prostheses. At the same time, atrophic candidiasis develops, a huge number of fungi accumulate in the buccal folds against the background of red pinpoint inflammation of the mucosa, invasion, as a rule, is absent.
Candidiasis esophagitis in general hospitals occurs in 1.3–2.8% of patients, in transplantation departments - up to 4%, with disseminated carcinomatosis - from 2.8 to 6.7%. This disease often proceeds without subjective complaints and is detected by chance during continuous studies of the population in 1–7% of cases 5, 17. Sometimes patients notice pain and discomfort during passage of solid and liquid foods, dysphagia, and hypersalivation. Four types of endoscopically are distinguished according to the depth of the lesion - from mild edema, hyperemia, single white patches
S. A. Burova, Doctor of Medical Sciences, Professor
National Academy of Mycology, City Clinical Hospital No. 81, Moscow