Beware of mycoses: fungal diseases are activated in summer

The undisputed leaders in terms of frequency of occurrence and global distribution among other infectious skin diseases are fungal diseases. In the general structure of skin diseases, mycoses range from 35 to 70%. The problems of fungal diseases become especially urgent in summer, when, due to increased sweating, increased contact through objects and walking barefoot in recreation areas, the risk of infection with various pathogens, including fungi, increases significantly.

Epidemiology of fungi affecting human skin

Onychomycosis is predominant among all diagnoses of dermatophytosis, the second place in terms of occurrence is occupied by mycosis of the feet, the third is mycoses of smooth skin.

The epidemiological conditions for the spread of fungal diseases are very diverse and have not been fully studied to date. The frequency of these diseases is primarily due to the abundance and diversity of fungi in nature, as a result of which there is a significant risk of infection for humans, as well as the significant biological variability of fungi, in particular, their ability to increase their pathogenicity and virulence under the influence of various factors.

Dermatophytes are called mold fungi - ascomycetes of the Arthodermataceae family, belonging to three genera - Epidermophyton, Microsporum and Trichophyton. In total, 43 species of dermatophytes are known, of which 30 are pathogens of dermatophytosis. In the process of evolution, pathogenic dermatophytes have adapted to life in various environments: in the earth (geophilic fungi), in human tissues (anthropophilic fungi) and animals (zoophilic fungi).

Anthropophilic dermatophytes cause fungal diseases only in humans. It is believed that they adapted to parasitize his skin during the evolution of geophilic and zoophilic fungi. Unlike mycoses caused by zoophilic fungi, anthropophiles are characterized not by a sporadic, but by an epidemic way of spreading the infection.

Clinical manifestations of fungal diseases of the feet

Lesions in anthropophilic infection are characterized by a mild inflammatory reaction and are localized, as a rule, in closed areas of the body (legs, inguinal folds), although a more widespread nature of the lesion is not excluded.

Athlete's foot, known as athlete's foot, is the most common anthropophilic fungal infection. Dermatophytes are the most common causative agents of intertriginous athlete's foot, but sometimes the interdigital folds become infected with fungi of the genus Candida, in rare cases, non-dermatophyte mold fungi such as Scytalidium (Hendersonula) cause infection of the skin of the foot.

Athlete's foot should be considered in the context of other fungal skin diseases, as lesions can spread to the soles, feet, palms, groin, and nails. The key link in this case is the development of intertriginous epidermophytosis of the feet. Most often, these complex infections are caused by dermatophytes.

Clinically, dermatophytosis of the foot mainly affects the interdigital folds of the feet, especially the lateral ones, but the reservoirs of the fungus can also be found in other places, in particular, on the soles. It has been established that the normal microflora of the interdigital folds of the feet is represented by staphylococci, anaerobic corynebacteria and a small number of gram-negative microorganisms. This microbial landscape is also preserved in the case of peeling in the folds, but fungi are found in the folds in 85% of patients. A sharp increase in gram-negative microorganisms leads to the development of a pronounced inflammatory reaction (maceration, weeping, erosion). It has been proven that the most severe course of the intertriginous process is observed in the interaction of dermatophytes and gram-negative microorganisms. With the addition of pyogenic microflora, inflammation in the lesions intensifies, purulent crusts appear, and lymphangitis and lymphadenitis often develop. Thus, it is believed that dermatophytes mainly cause skin exfoliation, while maceration and erosion of the skin usually occur under the action of bacteria.

The meaning of foot dermatophytosis is twofold. On the one hand, foot dermatophytosis is a contagious infection that spreads with the help of infectious particles, i.e. horny scales containing the fungus in public bathing areas, public showers, industrial premises, swimming pools, fitness centers, saunas, and within the family, where the main spread occurs in living quarters, in the toilet, in showers and through contact between family members. On the other hand, foot dermatophytosis plays an important role in the epidemiology of mycosis of large folds caused by Trichophyton rubrum, Trichophyton mentagrophytes var. interdigitale. Often both clinical forms are observed in the same patient. According to the literature,

Features of the course of skin mycosis in the inguinal folds

The disease is often observed in the inguinal folds in men, which is facilitated by increased sweating of the folds and scrotum, due to lifestyle and work, physical exertion, and frequent trauma due to wearing tight underwear. In addition, men are more likely to suffer from fungal infections of other parts of the body (especially the feet). A fungal infection of the scrotum skin plays an important role in the spread of mycosis in the inguinal folds in men, while its skin may look completely normal or slightly inflamed.

Usually, mycosis extends beyond the inguinal folds, spreading to the inner thighs, perineum, perianal region and intergluteal fold; possible isolated lesions of these areas. After wearing tight clothing, acute inflammation can develop. As a result of autoinoculation or primary infection, axillary cavities, folds under the mammary glands in women, elbows and popliteal fossae, as well as any area of ​​the skin, including the scalp, may be affected.

Initial manifestations are small, slightly edematous, pink patches with a smooth surface, rounded outlines, and sharp borders. As a result of an increase in size and merging with each other, they form a continuous focus with scalloped contours, prone to peripheral growth. The marginal zone of the focus, covered with vesicles, pustules, erosions, scales and crusts, in the form of a continuous roller, clearly protrudes above its center and the surrounding skin. Sometimes lesions of various configurations are formed, sometimes capturing vast areas of the skin. Subjectively - itching, from moderate to severe and even painful. Over time, inflammation in the foci of mycosis fades away (peeling appears, brownish tones begin to predominate in their color) or is resolved if the moist environment is eliminated.

It should be noted that in 3-5% of cases, candidiasis-mold fungi are an independent cause of damage to the inguinal folds. Such a lesion is more common in women and is almost always accompanied by a pronounced inflammatory reaction.

Mycosis of the inguinal folds in 35–40% of cases can be caused by E. floccosum, it is usually distinguished into a separate form of the disease - inguinal epidermophytosis, which usually begins acutely, but in the absence of rational treatment can be transformed into a chronic form.

Chronic mycosis of large folds can be complicated by lichenification, simulating limited neurodermatitis. The addition of a secondary pyococcal or candidal infection often complicates the course of mycosis, which is accompanied by the phenomena of weeping, maceration, and pustulation of lesions. This variant of the course of mycosis is possible with irrational treatment with the appointment of corticosteroid ointments. With prolonged use of irritating and sensitizing agents, the development of allergic dermatitis is possible.

Differential diagnosis and therapy of fungal diseases

Although the most common etiological factors leading to the development of skin fold lesions are pathogenic and opportunistic fungi, a differential diagnosis should be made with diaper rash (intertrigo, intertriginous dermatitis) caused by friction of contacting skin surfaces - the most common variant of dermatitis from mechanical influences . The incidence of intertrigo is especially high among obese patients with diabetes mellitus. The cause of the disease in this case is the friction of the contacting surfaces of the skin under conditions of irritating and macerating action of sweat.

In the treatment of lesions of the skin folds, accompanied by acute inflammatory phenomena of fungal, bacterial-fungal etiology, the dosage form of topical preparations is extremely important. This is due to the fact that the fatty components included in the formulation of the most commonly used dosage forms (ointments and creams) can contribute to the development of the so-called "greenhouse effect", provoking increased exudation and further spread of the infectious process on the skin.

In the case of skin fold lesions caused by dermatophytes and other most common pathogens of skin mycoses, the use of an external highly effective antimycotic - terbinafine in the form of a gel is indicated due to its antimycotic, antibacterial and anti-inflammatory action. It is the drug of choice in situations where the course of ringworm is accompanied by a pronounced inflammatory reaction and patients complain of itching and burning.

Thus, the gel dosage form of terbinafine is highly hygroscopic, air-permeable, with a pronounced cooling and anti-inflammatory effect, which makes it possible to achieve resolution of the process as soon as possible.