Nail fungus


The fingernail or toenail turns yellow to light brown and becomes thicker: nail fungus (onychomycosis) is spreading. It doesn't hurt or itch, but it looks ugly. In principle, nail fungus can be treated well - the earlier, the better. But patients need patience. The treatment of toenails in particular can take months. However, nail fungus does not heal on its own.

Overview: What is nail fungus?

Barefoot in the swimming pool, sauna or gym shower area without slippers and it’s already happened: A fungal infection has infected a nail. But nail fungus can also develop from untreated athlete’s foot. The infection is manifested by a yellowish or brown discoloration of the nail. Over time, the fungus eats its way deeper and deeper into the nail and gradually destroys the nail plate. Fingernails are less frequently affected as they grow faster and are exposed to the air more. Fungi, on the other hand, feel particularly at home in a moist, warm climate. Onychomycosis usually appears on the toenails. Without targeted treatment, the infection does not disappear and it is extremely contagious. You should therefore not share nail scissors, files or towels with other members of your household if you are ill.

Nail fungus – frequency and age

Nail fungus is a fairly widespread disease. It is estimated that around four percent of people in industrialized nations suffer from it. Onychomycosis occurs more frequently with increasing age. People who play sport and people with a lot of sweat on their feet suffer particularly frequently from the unpleasant nail fungus – the pathogens feel particularly at home where it is damp and warm. Men are more frequently affected by nail fungus than women. Fingernails are rarely affected by fungi. The disease usually occurs mainly on the nail of the big toe. However, if it is not treated, it will gradually spread to other toenails.

Nail fungus: causes and risk factors

Nail fungus is usually caused by fungal sprouts of the dermatophyte group. These are the spores that are also responsible for athlete’s foot. Mold or yeast fungi, on the other hand, are rarely the cause of onychomycosis. You come into contact with the spores of the fungi when showering or changing after sport or in similar environments. If the immune system does not manage to eliminate them in time, they penetrate the toenail or the skin next to it. Tiny injuries facilitate infection.

You are particularly at risk if you suffer from the following problems:

  • Immunodeficiency
  • Diabetes
  • Psoriasis
  • Foot sweat
  • Poor circulation in the feet (e.g. due to tight shoes)
  • Injuries to the nails and skin

Symptoms: Nail fungus causes yellow nails

The first signs of nail fungus can usually be seen on the right or left edge of the big toenail: It first turns yellow and then becomes thicker and rougher. If left untreated, this yellow area grows further and further into the nail. This begins to change, becomes more porous and loses its smooth surface. The fungus penetrates the horny layer of the nail and slowly dissolves it.

Experts distinguish between three different forms of onychomycosis:

  • Distolateral subungual onychomycosis: This nail fungus is particularly common. It first attacks the skin around the nail and then penetrates the nail plate from below and spreads there. This softens the nail from below and causes it to turn yellow.
  • Proximal subungual onychomycosis: This form is much rarer. The fungus attacks the nail from above at the nail root – i.e. where the nail grows out. From there, the fungus gradually spreads over the entire nail plate.
  • White superficial onychomycosis: This infection is caused by the fungus Trichophyton. The fungus only grows on the top layer of the nail keratin. This makes the toenail appear white.
  • Total onychodystrophy: The fungus has affected the entire nail, including the root. There is no healthy nail plate left. At this stage, nail fungus is difficult to treat.

Diagnosis of nail fungus

We immediately recognize the nail fungus from the altered surface of the nail. A magnifying glass is used to see how advanced the infestation is. To make sure which type of fungus is responsible for the damage to the nail, we cut off a piece of the nail, look at it under a microscope or send it to the laboratory for examination. Sometimes we also add a piece of the surrounding skin. The laboratory test is used to differentiate between other diseases with similar symptoms such as lichen ruber or so-called eczema nails. However, the type of fungus can only be determined if no antifungal agents have been used in the four weeks prior to taking the sample. However, in the case of an incipient fungal nail infection in particular, a visual inspection is often sufficient.

Nail fungus: prevention, early detection, prognosis

You can do a lot to protect yourself from athlete’s foot or nail fungus:

  • Change your socks every day and air out your shoes thoroughly every day.
  • Wash your towels at least once a week at 60 degrees.
  • Do not wear tight shoes and ensure good ventilation.
  • Wear your own slippers to the swimming pool and gym.
  • Disinfect your shoes – including slippers – regularly.
  • Dry your feet thoroughly, including between the toes, using a separate towel.
  • Do not share nail scissors and nail files within the family and disinfect them after use.
  • Use washable floor mats in the bathroom and wash them regularly.

Course and prognosis of nail fungus

If a foot or nail fungus does occur, treat it immediately and thoroughly! The earlier you start treatment, the more successful it will be. If you develop athlete’s foot or nail fungus, you should wash your socks with a hygiene rinse and change the towel every day.

Treating a nail fungus requires a lot of patience. Toenails grow much slower than fingernails and even slower in women than in men. On average, the nail of the big toe grows about 0.5 millimeters per week. With the other toenails it is often a little less. The growth rate continues to decrease with age. A fungal infection is only defeated when it has completely grown out of the nail. Even with a mild infection, it takes several months for the nail to heal completely. If you suspend treatment for even a short time, you risk the complete success of the treatment.

If a large part of the nail is infected, it often takes more than a year until the fungus is defeated. There is a high risk of relapse even after successful treatment: fungal spores can easily hide in small cavities under the nail. The fungus can spread again as soon as the antifungal medication is discontinued and you are in a warm and humid environment. Very careful hygiene is therefore advisable. All shoes and stockings as well as pedicure sets and towels should also be carefully disinfected after successful treatment.

Nail fungus: treatment with medical nail polish

The treatment of the fungal infestation depends on the type of fungus and how far it has already spread. If only a small part of the nail is affected by the fungus and only one nail is affected, treatment with special nail polish or (more rarely) a medicinal cream is often sufficient. As far as possible, you should remove the nail destroyed by the fungus and then regularly apply cream or nail polish, or both. It is important that you treat the affected area as well as the surrounding area thoroughly. It is best to remove dead parts of the nail regularly, before starting treatment you can disinfect the nail first. Take care not to injure the skin of the toes during treatment.