Onychomycosis and nail fungus in the photo: symptoms, treatment, prevention

Onychomycosis of the nails often occurs in people with weakened immune systems, because in a normal state, the immune system of the epithelial and stratum corneum does not allow the penetration and rooting of the fungus.

One of the most common skin diseases in the world is onychomycosis, a fungal nail infection caused by dermatomycetes, yeasts or molds. According to the latest data, the number of patients with onychomycosis in Russia varies from 4.5 to 15 million people. A fungal infection can significantly poison the existence of its owner, both because of the aesthetic side of the issue – yellow crumbling nails, the inability to wear open sandals or go to the pool, and due to the fact that fungi weaken the immune system and provoke allergic reactions.

Fungal nail infection

Fungal infection of the nails depends on many factors:

Climate – fungal infections are often found in countries with a temperate and cold climate, whose inhabitants constantly wear shoes that create favorable conditions for the development of infection. Age-related onychomycosis affects mainly middle-aged and elderly people. It is believed that the incidence of onychomycosis increases with age by 2.5 times every 10 years and increases from 3% in children and adolescents to 50% in the elderly.

Gender – men suffer from onychomycosis 1.5-3 times more often than women. Concomitant diseases – predisposing to onychomycosis are peripheral angiopathy (venous insufficiency, Raynaud's syndrome), obesity, foot deformities, diabetes mellitus, in which the incidence increases to 30%, as well as various immunodeficiencies.

Profession – the risk group includes, first of all, people who visit common areas every day (cloakrooms, showers, etc.). The most predisposed group are professional athletes. The risk group is military personnel using uniform shoes (boots and heavy boots), as well as sailors. The same risk factors predispose industrial workers to fungal infection. However, often in order to become the owner of the fungus, you do not even need to leave your own apartment. Many people become infected with the fungus in the family through shared shoes, clothing, household items.

Causative agents of fungal infections: fungi of the genus and type Candida

Currently, there are about 50 types of fungi that can infect nails. All pathogens of fungal infections are divided into 3 groups: dermatomycetes, yeast-like fungi of the genus Candida and mold fungi. The main causative agents of fungal nail infections are dermatomycetes, which account for about 80-90% of cases of onychomycosis.

The most common are: Trichophyton rubrum, Trichophyton mentagrohytes and Epidermophyton floccozum. In Russia, Western European countries and the United States, about 80% of all cases of onychomycosis are caused by T. rubrum. In second place in terms of frequency of occurrence among dermatophytes is T. mentagrophytes, which accounts for about 10-20% of cases of nail dermatophytosis.

The second most common causative agents of onychomycosis after dermatophytes are fungi such as Candida, the proportion of which among the causative agents of onychomycosis is 5-10%.

Among the mold fungi in the nail plates, the following species are more often detected: Aspergillus spp., Fusarium spp., Acremonium spp., Scopulariopsis brevicaulis, Scytalidium spp.

Pathogenesis and fungus onychomycosis

As mentioned above, the main causative agents of onychomycosis are dermatomycetes. These fungi are characterized by a pronounced ability to destroy and absorb keratin. Dermatomycetes have a wide range of enzymes that allow them to penetrate the skin and nails. As a rule, dermatophytes affect the skin of the feet, and then spread to the nails. Onychomycosis fungus penetrates the nail in 3 ways:

• through the subungual notch from under the free edge of the nail plate;
• through the dorsal part of the nail plate;
• through the nail fold.

Most often, dermatomycetes are introduced into the nail from under the edge of the nail plate, while the main pathological processes do not occur in the plate itself, but under it, in the nail bed. The nail bed responds to the invasion of the fungus by accelerating proliferation, which leads to the formation of subungual hyperkeratosis. Thickening of the stratum corneum at the edges of the nail bed disrupts the connection of the bed with the nail plate, as a result of which separation of the plate from the nail bed begins in the early stages. From the nail bed, pathogens spread to the nail plate and cause its slow destruction. As a rule, T. rubrum affects the nail plate in this way.

Some fungi are able to penetrate the nail directly through the nail plate – these are fungi that have a pronounced keratolytic ability. These dermatomycetes include T. mentagrophytes.

The third way that fungi enter the nail is through the nail fold. From there they penetrate under the nail plate, into the bed and cause degenerative changes in the nail.

A different way of penetration into the nails is observed with candidiasis of the nails. With it, inflammation of the proximal roller first occurs – paronychia. Swelling, thickening and changes in the shape of the roller cause the skin of the nail to separate from the surface of the nail plate. It should be noted that candidal onychomycosis is much more common on the hands than on the legs.

Most mold fungi are considered unable to independently cause onychomycosis, however, some of them are recognized as independent pathogens – these are S. dimidiatum and S. hyalinum. Infections caused by these fungi occur in countries with a tropical climate.

The introduction of fungi into the nail area is usually preceded by damage or destruction of the structures limiting it. These factors include:

• injury to the nail plate;
• constant contact with water, synthetic detergents, degreasers;
• wearing tight, narrow shoes made of synthetic materials (creating a moist and warm environment conducive to the growth and reproduction of fungi);
• use of infected manicure and pedicure tools;
• increased sweating;
• various deformations and anatomical features of the foot (flat feet, narrowness of the interdigital spaces).

Symptoms of a fungal infection

Domestic dermatologists distinguish three types of onychomycosis: normotrophic, hypertrophic and onycholytic. The symptoms of a fungal infection depend on the form of the disease.

In the normotrophic type, only the color of the nails changes, the nail plate retains its shape and thickness for a long time. However, spots and stripes appear inside the plate itself, the color of which varies from white to yellow. Gradually, the entire nail changes color, without changing its thickness.

In the hypertrophic type, the nail plate thickens due to the development of subungual hyperkeratosis, the nail loses its luster, becomes dull, thickens and deforms. Erosion appears on the free edge of the nail plate in front and on the sides. With this form of onychomycosis of the feet, patients may experience pain when walking.

The onycholytic type is characterized by a rapid separation of the nail plate from the nail bed, while the nail becomes dull, has a brown or gray color. The exposed area is covered with loose layers.

What does nail fungus and candidal onychomycosis look like?

Foreign dermatologists distinguish forms of the disease candidal onychomycosis according to its localization:

• distal (damage to the nail at the free edge);
• lateral (damage to the sides);
• proximal (damage to the posterior roller);
• total (damage to the entire nail).

The photo shows what the fungus on the nails looks like:

Diagnosis of nail fungus

When you notice signs of onychomycosis, don't expect it to go away on its own. The longer the fungus lives on your nails, the more difficult it is to treat. Therefore, at the first suspicions, you should consult a dermatologist for further diagnosis of nail fungus and treatment.

For laboratory diagnosis of onychomycosis, microscopic and cultural studies are used. Microscopy is performed using 10-30% caustic potassium solution to dissolve the keratin, and gives a conclusion about the fungal nature of the infection, but not about the type of fungus. For cultural research, sowing of the material on nutrient media for fungi is used. Species identification is usually carried out by microscopic examination of the grown culture or by subculture on selective media.

Treatment of onychomycosis

Treatment for onychomycosis is either a topical antifungal drug applied to the affected nail, or systemic, when the drug is given orally and enters the nail plate through the bloodstream. The disadvantage of local therapy is that when the drug is applied to the surface of the nail, it does not always reach the pathogen that can not only affect the nail plate, but also penetrate into the nail bed and deep layers of the skin, especially with total onychomycosis. As practice shows, local treatment alone in most cases does not lead to a complete cure of patients. As external antifungal agents, keratolytic ointments and patches are used to mechanically remove the affected part of the nail and nail polishes containing antifungal agents: traditionally used mixtures of lactic, benzoic, salicylic acids,

Ways to treat nail fungus

There are other ways to treat nail fungus. To date, the most relevant is the systemic therapy of onychomycosis. Recently, new generation antifungal drugs have been synthesized, which can increase the effectiveness of therapy up to 80-90%. The most commonly used drugs for the treatment of onychomycosis in adults are terbinafine and itraconazole, in young children fluconazole (due to its high safety profile). The fungistatic concentration of drugs remains in the skin and nail plates for several months after the end of treatment, which significantly increases the percentage of complete cure.

Prevention of nail fungus

Prevention of nail fungus is to follow simple rules:

• on the beach to walk only in shoes;
• use closed rubber slippers in the bath or pool;
• after washing, dry the feet, especially the interdigital folds, treat them with a prophylactic antifungal cream or powder;
• do not wear someone else's shoes;
• change socks and tights daily.