Caution, nail fungus • The 9 most important risk factors

The most common – over 90 percent – onychomycosis is caused by filamentous fungi. These dermatophytes include pathogens such as Trichophyton rubrum or Trichophyton interdigital. In five to ten percent of cases, yeast (mostly Candida species) triggers the nail fungus. Mold is the cause of five percent. The pathogen is then usually Scopulariopsis brevicaulis identified.

Numerous risk factors favor nail fungus

The pathogens for nail fungus can be found everywhere in our environment. But not everyone inevitably suffers from it. A healthy and dry skin as well as an intact nail protect very well against a nail fungus infection.

The fungus pathogens feel particularly comfortable in the warm, damp climate of the shoes. Those who suffer from sweaty feet are therefore at greater risk of nail fungus. If there are also small cracks and injuries and other risk factors, it is easy to become infected with nail fungus.

The most important risk factors at a glance:

Risk factor 1: athlete's foot

Athlete's foot infection with itchy feet and scaly skin between the toes is very often the first step to nail fungus. Athlete's foot infection is usually limited to the area between the toes, the sole of the foot or the heel. However, athlete's foot attacks the skin and makes it more susceptible to the nail fungus. If no treatment is started, the infection can spread and lead to nail fungus. This is then even more difficult and lengthy to treat.

Risk factor 2: weakened immune system

Our body's immune system has the task of keeping pathogens, i.e. bacteria, viruses and fungi, away. But sometimes this immune system is too weak. This applies, for example, to people who suffer from an immune deficiency or who have to take medication that suppresses the immune system. You can get such medications, for example, after an organ transplant or for diseases such as rheumatism or cancer. The risk of skin or nail fungus is therefore greater in these patients than in healthy people.

Risk factor 3: diseases such as diabetes and psoriasis

Not only a weakened immune system, but also other diseases and physical conditions can favor fungal infections. These include diabetes, venous insufficiency, lymphatic damage or skin diseases such as psoriasis or neurodermatitis. In these clinical pictures, among other things, inflammatory and scaly nail changes can occur, which allow fungus pathogens to penetrate easily. Erythroderma can even lead to nail loss. People who suffer from nail melanoma are also at greater risk.

Diabetics are even at multiple risk: the disease weakens the immune system and thus the body's defenses against intruders such as nail fungus germs. The blood flow in the fine capillaries of the fingertips, the toes and the nail bed deteriorates and the fungus can adhere more easily.

The skin of diabetics is also drier, often becomes brittle and cracked – small skin injuries offer the fungus ideal entry points. Since diabetics are often also less sensitive to pain, they often do not feel any injuries or symptoms caused by fungal infections.

Therefore, diabetics should pay particular attention to good foot hygiene and early signs of fungal infections. Check your feet for blisters, pressure marks and cracks every day. The key to good prophylaxis is consistent and good blood sugar control. It contributes to good blood circulation and increases resistance to infection.

Risk factor 4: impaired blood circulation

If the blood flow to fingers or toes is disturbed, skin changes can occur. Athlete's foot or nail fungus are then easy to play.

Healthy nails are supplied with oxygen and nutrients by blood vessels in the toes and fingers. In the case of diseases such as Raynaud's syndrome, peripheral arterial occlusive disease (abbreviation: PAD) or chronic venous insufficiency (CVI), this blood flow is disturbed. These diseases lead to growth disorders on the nails and pathological changes in the skin and nails and an increased susceptibility to the nail fungus pathogens.

Risk factor 5: misaligned feet

Misaligned feet and deformities of the feet acquired during life often cause pain. They increase the pressure on the toenails, the normal rolling of the foot can be difficult. In addition, the deformation in the toe area results in increased pressure on the nails, which in turn favors nail fungus. With the hammer toe, the individual toes are difficult to bend apart – this easily creates sore, inflamed areas, which in turn promotes the penetration of athlete's foot.

If there are any cracks or small wounds, it is advisable to watch them carefully. If they enlarge, a visit to the doctor is necessary. Men and women with poor circulation in the legs and feet, in particular, have to be careful: small injuries can quickly expand with oxygen and nutrients because of the poor wound supply via the blood vessels.

Risk factor 6: age

In older people, there are often several risk factors for a nail fungus infection. Your immune system is no longer working at full strength, which means that germs can be fought less effectively. In addition, older people are more likely to suffer from diseases that weaken the immune system or lead to poor circulation in the feet. Taking certain medications and malnutrition also reduces the immune system's defenses.

In addition, the skin becomes thinner, drier and more brittle with age, and the quality of the nail plates deteriorate. Injuries, wounds or fissures are more common, heal less well and thus provide entry points for fungal pathogens.

Risk factor 7: Exercise or active occupation of the feet

The accumulation of nail fungus in athletes has various reasons. First of all, the high risk of infection in sports facilities (changing rooms, showers) should be mentioned. Where there are many people, there is often someone with nail fungus. But not only this fact makes a yeast infection likely in athletes.

One-sided, constantly repetitive movements put a particular strain on the feet and toes. Small injuries from chafing, blisters or small cracks are a prerequisite for the entry of the fungal pathogens and make an infection possible in the first place. In some sports, the risk of becoming infected with nail fungus or athlete's foot is particularly high. These include swimming and soccer, as well as the endurance sports of cross-country skiing, triathlon and marathon. Recreational sports such as tennis, squash, trekking, hiking and inline skating also show considerable infection rates.

Even in rental shoes (e.g. ski boots, bowling shoes), fungal spores can sometimes survive despite disinfection. Those who are at risk should better use their own equipment.

Those who move a lot and do physical work in the job also put a lot of strain on their feet. For example, there is a high risk of nail fungus for construction professions, service personnel from the catering trade or employees in the retail trade.

Risk factor 8: improper care

Nail polish and artificial nails can also promote nail fungus. Commercial nail polish can block the ventilation of the nail and thus offer the fungi ideal growth conditions. In addition, acetone-containing nail polish remover removes fat-soluble substances from the nails, which changes the natural structure of the nail and restricts its function. Above all, people who are susceptible to nail fungus should avoid the cosmetic decoration of their toenails and fingernails. Even in the event of a possible infection of the nail, it is advisable not to cover any discoloration and deformation with a coat of paint.

The same applies to artificial fingernails: they are placed with an adhesive substance so tightly on the natural nail that the fine-pored nail structure is closed. This means that there is no sufficient air exchange and the moisture that normally accumulates under the nail surface and is released through the nail pores can then no longer escape. However, fungal spores can easily gain a foothold on permanently moist nails, because moisture is a factor that promotes fungal growth.

Lack of hygienic conditions (such as lack of disinfection) and insufficiently trained staff can also transmit nail fungal diseases in nail studios.

Improper foot care can also lead to infection with nail fungus. If files, scissors and other tools are used too harshly, the smallest injuries can occur. These form entry points for the fungi, which also find ideal living conditions if the feet are not sufficiently dry.

Risk factor 9: infection in swimming pools, saunas, hotels – and at home

Especially where there are many people on the go and there is also a humid and warm climate, there is a great risk that fungal pathogens are on the go and you are infected. The risk of infection for nail and athlete's foot is great, especially when walking barefoot in swimming pools, outdoor pools and the sauna. Both healthy and particularly vulnerable people should observe some rules of conduct and hygiene so that no unwanted souvenir is left after bathing or wellness fun. If you already have nail fungus, you can protect others – without having to do without a visit to the swimming pool or swimming pool.

This applies, for example, to hotel rooms, hotel bathrooms and wellness facilities – even if they are cleaned regularly.

The infection with nail or athlete's foot in your own four walls should not be underestimated. Those affected can easily transfer the fungal infection to other family members through shared towels, manicure tools, laundry that has not been washed sufficiently, or walking barefoot in their own four walls. Simple behavioral tips and hygiene rules help not to infect others.

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