One in ten people suffers from athlete's foot, and it recurs repeatedly. Why is athlete's foot so difficult to eradicate?

Author: Yao Zhiyuan, Chief Physician of Dermatology Department, China-Japan Friendship Hospital

Member of the Mycology Group of the Dermatology and Venereology Branch of the Chinese Medical Association

Reviewer: Chen Yong, Chief Physician, Beijing Chaoyang Hospital, Capital Medical University

Athlete's foot is also known as tinea pedis. Tinea pedis is the medical name, and athlete's foot is the common name among the people.

Athlete's foot is a very common skin disease caused by fungal infection. After the fungus infects the skin of the feet, it causes a series of inflammatory reactions in the skin.

Based on clinical manifestations, athlete's foot is divided into several types.

The first type is the blister type, where many small blisters appear between the toes or on the soles and sides of the feet. These small blisters are relatively deep, some look shiny, and are accompanied by itching;

The second type is immersion erosion, which mainly occurs between the third and fourth toes, or between the fourth and fifth toes. These two places are the least breathable and most suitable for fungal reproduction. They appear red and white, caused by long-term immersion, and are also accompanied by itching.

The third type is keratotic type. If athlete's foot is not treated for a long time, the skin will gradually become dry, thickened, and even crack and peel.

Figure 1 Original copyright image, no permission to reprint

With the above clinical manifestations, plus local fungal examination, a positive fungal test can confirm that it is athlete's foot.

The prevalence of athlete's foot is particularly high. According to statistics from home and abroad, in the normal population, about 10 out of every 100 people will get athlete's foot. Some special groups, such as coal miners, who always wear rubber shoes that are not breathable, may have an incidence of athlete's foot of more than 50%, and 5 out of 10 people will get athlete's foot.

1. How is athlete’s foot usually contracted?

Many people ask, "I pay great attention to hygiene and wash and change my shoes and socks regularly, so why do I still get athlete's foot?" Under what circumstances are the feet most susceptible to fungal infections?

First, public baths. Public slippers and floors are not disinfected well.

Second, sharing shoes, socks and foot basins often occurs in families.

Therefore, it is not enough to just pay attention to personal hygiene, we also need to pay attention to public health.

Are you more likely to get athlete's foot if your feet sweat a lot and you don't change your shoes often?

From a medical point of view, after fungi infect the skin of the feet, the temperature suitable for fungi to grow is 25℃-37℃ and the humidity is 95%-100%. Fungi are easy to reproduce in a hot and humid environment. Sweaty hands and feet, and not changing shoes frequently are indeed prone to athlete's foot. Fungi are not easy to survive in a dry environment.

If you experience symptoms, do not take medication indiscriminately. Go to a regular hospital for a check-up. After a confirmed diagnosis, take targeted medication under the guidance of a doctor.

2. How to treat athlete’s foot?

The principles of treatment for athlete's foot are: first, eliminate the fungus; second, relieve symptoms; third, prevent recurrence.

For blister type, it is not suitable to use ointments with strong irritation. Use milder or aqueous antifungal drugs;

For erosion type, treat the erosion first. It is not suitable to apply ointment directly. If there is erosion and exudation, applying ointment will block the exudation and is not conducive to treatment. Apply some solution wet compress, and after the exudation is reduced, apply ointment or medicine with less irritation;

For the keratinized type, the stratum corneum is very thick, so some stronger antifungal drugs should be used in combination with drugs containing keratin exfoliating ingredients to soften the keratin.

If topical medications are not effective, the patient has poor immunity, or blood circulation in the lower limbs is not good, oral antifungal drugs may be needed. Combined topical and oral treatment will be more effective.

It should be noted that athlete's foot cannot be treated with hormone ointments, because hormone ointments will have a nutritional effect on the fungus. After the fungus "eats" the hormone, it will grow more vigorously, and the hyphae will become more enlarged. The more it is used, the heavier the disease will be and the larger the range will be.

There are two standards for judging whether athlete's foot is cured, one is clinical cure and the other is mycological cure. After a period of treatment, the fungus should be rechecked. If the fungus is gone, it is called mycological cure. Clinical cure means that the patient has no symptoms. Clinical cure plus mycological cure, double cure is the most perfect and ideal state.

In theory, athlete's foot should be easy to treat, but in reality, athlete's foot is a very difficult skin disease to cure. Many patients say that athlete's foot is very difficult to treat, and it always recurs. Why is this?

3. Why is athlete’s foot so difficult to eradicate?

First, the keratin of the foot skin is very thick, and the drug is not easy to penetrate after being applied. Usually a relatively long treatment time is required, and patients sometimes find it difficult to persist, and the compliance of medication is relatively poor. Many patients use the medicine for two days, and then stop taking it when they feel that the symptoms are better and the itching is gone. The topical medication treatment is not in place, and the fungal cure is not achieved.

Generally speaking, it is recommended to use medicine for at least two to four weeks to treat athlete's foot, which is a relatively long time. Of course, the specific time of use should also be determined according to the condition of the disease.

Different drugs should be used to treat athlete's foot according to different clinical manifestations. You can't just randomly use some antifungal drugs to treat it. This is definitely not the right way. Different drugs are used for blister type, erosion type, and keratosis type.

In addition, personal items should be disinfected and sterilized to prevent reinfection. Develop good hygiene habits and be aware of protection when going to public places.

Figure 2 Original copyright image, no permission to reprint

In general, a sufficient course of treatment and combined use of medication as needed are very helpful in curing athlete's foot.