Fungal Infections

General Illness Information

Medical Term: Eczema

Common Name: fungal infections, fungus infections. fungal diseases, fungal skin infections.

Description: Fungal infections are infectious diseases, caused by representatives of fungi. These include heterogeneous infections, most of which occur against the background of immunodeficiency states.

Classification: Fungal infections are divided into the following forms (by type of pathogen):

• Candida infections (fungus of the genus Candida);
• Trichophytosis (fungal infections of the skin, nails, mucous membranes);
• Cryptococcosis (fungus affects the lungs and internal organs);
• Aspergillosis (infectious disease of the lungs on the background of decreased immunity).

Fungal infections are divided into 2 groups (by localization):

1. Superficial fungal infections – infecting the skin and mucous membranes, without spreading the pathogen to internal organs (infections caused by fungi of the genus Candida, Trichophytosis);
2. Systemic fungal infections – characterized primarily by the defeat of internal organs and dissemination of microorganisms with blood (cryptococcosis, aspergillosis).

It is important to note that systemic fungal infections occur against the background of immunodeficiency states. So a large amount of spores of Aspergillus fungus daily gets into the human body, however the disease does not develop due to the work of the cell link of immunity. However, with reduced immunity, activation of aspergillus and systemic fungal infection occur.

Etiology: The causative agents of fungal infections belong to a separate realm of living organisms – fungi. They were separated into a separate kingdom because of their characteristic features, namely:

• Like plants, they are unable to move, but contain no chlorophyll and have no ability to synthesize organic substances from water and carbon dioxide;
• Have a resemblance to the animal kingdom by the exchange of substances and method of nutrition, but have no cells of the nervous system (neurocytes) and no muscles;
• Have a cell wall consisting of chitin, whereas in plants the basis of the cell wall is cellulose.

According to the method of extracting nutrients, representatives of fungi are divided as follows:

• Saprophytes – nutrient organic substances are extracted from the environment, more often from humus (conventional forest mushrooms);
• Parasites – nutrients are extracted through parasitism on another living organism (pathogenic and opportunistic fungi).

Routes of infection: The infectious agents in fungal infections are spores that enter the human body from the environment. The routes of infection are almost the same as for all other infections:

• alimentary – a rare way of infection, it happens when fungi of the genus Candida enter the mouth with food, where infection develops on the mucous membrane (thrush of oral mucosa in children);
• air-dust – the transmission pathway typical for systemic fungal infections, with spores of aspergillus and cryptococci that can persist in the environment for a long time, enter the lungs and cause disease (with reduced immunity);
• contact route of transmission – happens with all superficial fungal infections with skin lesions (dermatophytosis), the infecting onset can be spores or mycelia of the fungus of a sick person, can be direct and indirect (via joint use of shoes), contact route;
• the sexual route of infection.

Some species of fungi of the genus Candida can be present on the mucous membranes of the human body from birth, being a conditionally pathogenic flora. Only with a decrease in immunity, candidiasis starts to develop. In the case of a significant decrease in the activity of the immune system (especially the cell link in HIV AIDS), development of systemic candidiasis with the defeat of almost all internal organs is possible.

The mechanism of development: All fungi are extracellular parasites. After spores or mycelia enter favorable conditions, they grow into vegetative form, which multiplies, feeds from nutrients from the tissues of the body and multiplies with the release of new spores and mycelium, which are released into the environment. At the same time, there released metabolic products that have toxic and allergenic properties and cause local and general reactions in the form of inflammation and intoxication. Protection of the human body is carried out due to the cellular link of the immune system, but complete destruction is possible only by using antifungal agents.

Prevention: The prevention of fungal infections includes some personal hygiene measures:

• use only your own means of hygiene, footwear, clothing;
• wash hands after visiting public places, transport;
• sterilization of instruments, which are used in hairdressing salons, tattoo parlors;
• use of a condom with irregular sexual intercourse, especially women, since the risk of developing candidiasis of the vaginal mucosa (thrush) is high.

Preventive maintenance of systemic fungal infections is directed on maintenance of immunity and prevention of its decrease:

• correct organization of work and rest;
• proper sleep (not less than 8 hours), its quality (the time of sleep, in which the body rests as much as possible is 22.00 to 6.00);
• proper nutrition with sufficient intake of vitamins (especially important in the winter-spring period of hypovitaminosis);
• avoid long-term stresses, since “exhausted” nervous system reduces the activity of the immune system;
• prevention of infection with other infections that lead to immunodeficiency – prevention of infection with the hepatitis B, C, HIV infection.

Signs & Symptoms:

Symptoms of fungal infections depend on the type of fungi.

With superficial fungal infections, there are the following local symptoms of the disease (on the skin or mucous membranes):

• redness – the main symptom on the skin and mucous membranes, indicates the presence of inflammation (candidiasis, trichophytosis);
• itching – the second most frequent symptom, also localized at the site of infection, often unbearable, worse at night (trichophytosis);
• violation of hair growth or their loss – pathognomonic (characteristic for one disease) symptom of ringworm;
• skin peeling – fungal growth in the skin causes reactive hyperkeratosis, death of epidermal cells, this leads to the accumulation and sloughing of dead cells (trichophytosis);
• thickening and deformation (violation of the shape of the nails) – in case of a fungal infection of the nail plates;
• white, cheesy plaque on the inflamed mucosa is a characteristic symptom of candidiasis (thrush).

Symptoms of systemic fungal infections are determined by which organ or group of organs are affected:

• cough – accompanies lung damage with aspergillosis and cryptococcosis, cough is present for a long time, can be dry;
• violated rhythm of cardiac activity;
• renal failure;
• fever – develops when the fungus enters the blood and its hematogenous (with blood) spread throughout the body.

Diagnosis: Basing on the structure and activity of fungi, the diagnosis differs from that of bacterial infections. The following basic methods are used:

• collection of anamnesis, listening of complaints and objective examination, in which the characteristic clinical symptoms of fungal infection are revealed (the method is common for superficial fungal infections);
• microscopy of the material – raids in candidiasis, the characteristic cells of the oval form are determined under the microscope;
• luminescent glow – a special fluorescent lamp is used, which reveals the fungal infection (on the skin);
• the PCR method (polymerase chain reaction) makes it possible to identify the genes of a particular fungal infection in the test material;
• the method of growing crops using special nutrient media.

For diagnosis of systemic fungal infections, the following methods are also used:

• X-ray lung examination – reveals changes in pulmonary tissue;
• Computer tomography – allows to diagnose small changes in internal organs;
• Ultrasound is a less informative diagnostic method, however, due to safety and lack of radiation, it can be used in children and pregnant women;
• Serological method – determines the titer of antibodies to a particular fungal infection.

Treatment: 

The most important treatment is etiotropic therapy, aimed at destroying the fungus in the body. For this, different classes of antifungal agents are used:

1. local remedies (used to treat superficial fungal infections) in the form of ointments, liquids or lotions. They are used for a long time, after the disappearance of clinical symptoms – during the first month.
2. medicines for systemic therapy – in the form of tablets and solutions for intravenous infusion. In severe systemic fungal infection (aspergillosis, cryptococcosis), intravenous drip infusion of antifungal agents is used.

Pathogenetic therapy is used to treat systemic fungal infections and includes:

• detoxication therapy – is aimed at reducing the number of toxins and metabolic products of fungi in the blood (intravenous drip infusion of saline solutions and sorbents);
• immunomodulating therapy – since systemic fungal infections occur against a background of reduced immunity, this type of therapy is very important, different classes of immunomodulators are used (laferobion, thymine, etc.);
• therapy aimed at restoring the function of internal organs damaged by a fungal infection (cardiac drugs, agents that improve renal blood flow).

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