Author: Liu Xiang, pharmacist in charge of Shanghai Deda Hospital
The weather in the south is humid and cold, do you have this experience: heel cracks, the skin at the crack is thick and hard, drilled like a knife on the ground, soaked in white vinegar, smeared with petroleum jelly wrapped in plastic wrap, or repeatedly cracked, hooked sheets, scraped socks, cracked and bleeding?
You may have athlete's foot!!!
What is tinea pedis?
Tinea pedis (commonly known as athlete's foot, "athlete's foot") is a skin disease of the feet caused by pathogenic fungi, which is contagious and belongs to one of the clinical subtypes of dermatophyte infection
Ringworm is widespread throughout the world and is more prevalent in tropical and subtropical regions. From the regional epidemiological survey data, the global natural population incidence is more than 10%, such as the average incidence in Europe is about 14%, and the incidence in most other regions is 18%~39%. In superficial fungal infections of the skin, tinea pedis accounts for more than 1/3. In the mainland, the incidence of tinea pedisis is also quite high. In the mainland, according to the data of China Foot Care Week, one in every two people has foot disease, and the incidence rate of adults is as high as 75%, and more than 60% of foot diseases are fungal infections, of which the incidence of tinea pedise (commonly known as athlete's foot) is 45.2%, and onychomycosis (commonly known as nail fungus) accounts for 15.5%, which is the highest incidence of foot disease
High susceptibility. Dermatophytes can spread from person to person, animal to person, pollutant to person.
Tinea pedis has a certain family susceptibility, especially the "two-legged and one-handed" type of tinea pedis is more prominent, which can be infected due to mixing shoes and socks, walking barefoot in public baths, gyms, swimming pools and other places, and close contact with pathogenic bacteria.
Superficial fungal infections can also spread themselves between different parts of the patient, such as tinea pedis can cause tinea manure, jock itch and onychomycosis, such as about 1/3 of patients with tinea pedis often accompanied by onychomycosis.
Environmental factors also play a role in the pathogenesis of superficial fungal infections, and hot and humid areas and high temperature seasons are precipitating factors for the high incidence of dermatophyte infections.
Excessive sweating of hands and feet, wearing breathable shoes, or impaired immune function are also important predisposing factors.
Skin lesions in tinea pedis tend to occur unilaterally (i.e., one foot) and then spread to the opposite side weeks or months later. Skin lesions are well-defined and can gradually extend outward. As the disease progresses or scratches, erosions, exudates, or even bacterial infections may occur, pustules, etc.
How does the fungal infection that causes tinea pedis come about?
There are no sebaceous glands between the soles and toes of the human foot, so there is a lack of fatty acids that inhibit the skin filamentous fungus, resulting in poor natural physiological defenses; However, the skin sweat glands in these parts are very rich, sweating more, coupled with poor air circulation, local humidity and warmth, which provides favorable conditions for the growth of filamentous fungi. In addition, the stratum corneum of the skin at the bottom of the foot is thicker, and the keratin in the stratum corneum is a rich nutrient of the fungus, which is also conducive to the growth of the fungus.
Who is susceptible to tinea pedis?
1. During pregnancy, due to changes in hormone levels in the body, women in pregnancy have a decrease in the skin's ability to resist fungal infections and are prone to tinea pedis.
2. Obese people are prone to athlete's foot due to dampness between the toes and impregnation of sweat.
3. Foot skin trauma destroys the defense function of the skin and is also one of the factors that induce athlete's foot.
4. Diabetic patients are also prone to athlete's foot due to lack of insulin, resulting in substance metabolism disorders, increased skin sugar content, resulting in decreased resistance.
5. Long-term use of drugs such as corticosteroids and/or immunosuppressants by antibiotics will cause normal skin flora imbalance and will also increase the susceptibility to tinea pedis.
6. Bad living habits related to some people do not pay attention to foot cleanliness and footwear, which provides a good breeding place for fungi.
7. The infection can come from other infected people or infected cats and dogs.
8. In addition, there are infections obtained from fungal colonies, such as:
●Shower room
● Changing room floor
●The area near the pool
9. If a fungal infection occurs in one part of the body, it may also spread to other parts. For example, men with fungal infections of the feet sometimes spread it to the groin area.
What are the classifications and manifestations of tinea pedis?
1. The clinical manifestations are blistering, peeling or white and wet skin between the toes, erosion or thickening, roughness, cracking of the skin, and can spread to the plantar and edges, severe itching.
2. It can be accompanied by local suppuration, redness, pain, inguinal lymph node swelling, and even the formation of secondary infections such as calf erysipelas and cellulitis.
3. Due to scratching the itchy place with the hand, it is often infected to the hand and the hand ringworm (goose palm wind) occurs.
4. When the fungus grows on the nails, it becomes onychomycosis (nail fungus).
5. Fungi like humid and warm environment, hot and sweaty in summer, wearing rubber shoes and nylon socks to provide a hotbed for fungi; In winter, the condition is much better, manifested by cracked skin.
There are the following types:
A. Blister type
Mostly occurs in summer, manifested as between the toes, foot margin, soles of the appearance of rice grain size, deep in the blister, evacuation or group distribution, the blister wall is thicker, the content is clear, not easy to rupture, fuse with each other to form multilovary blisters, tear off the blister wall, visible honeycomb base and bright red erosion surface, severe itching.
B. Erosive type
It is manifested as local impregnation and whitish of the stratum corneum. Due to constant friction when walking, the epidermis falls off, revealing a bright red erosion surface; In severe cases, the skin between the toes, the junction of the toe abdomen and the sole of the foot can be affected, and the itching is severe, mostly between the 3rd, 4th, and 5th toes. Common in hyperhidrosis.
C. Scaly keratotic type
Symptoms are thickening, roughness, scaling of the skin of the plantars, margins of the feet, and heels, and scaling into flakes or small dots, which are repeatedly shed.
Mode of treatment
It is divided into local treatment, systemic therapy, and local combined systemic therapy.
Topical treatment
There are erosions and exudations between the toes
Do not use external irritating drugs, it is best to let the wound converge and dry before using the drug. You can use 1:8000 potassium permanganate solution to wet compresses, then apply oil or powder externally, and switch to cream or ointment such as terbinafine hydrochloride after the skin is dry.
If the skin keratosis is severely thickened, it is difficult for antifungal drugs to penetrate and absorb
You can first use 10% salicylic acid ointment or compound benzoic acid ointment to soften the keratin, and then use antifungal drugs. If the skin is obviously dry and cracked, you can soak it in warm water each time to soften the keratin, and then use antifungal drugs. If the skin is dry and cracked, you can apply ointment locally after each warm water soaking, and then wrap it with plastic film, wrap a bandage, remove it after 24~48 hours, and then use antifungal drugs.
Small blisters on the feet, unruptured
You can first soak with 3% boric acid solution, and then choose antifungal creams such as bifonazole cream.
Systemic therapy
With stubborn tinea pedis, in the absence of contraindications, oral drugs can be given. Such as terbinafine, itraconazole, fluconazole, etc. These oral drugs have good effects, but attention should be paid to their possible side effects, and those with poor liver function are contraindicated.
Combination therapy
If tinea pedis combined with bacterial infection, consider using furacillin solution or 1:2000 berberine solution wet compress, severe infection, oral antibiotics, such as cephalexin capsules, erythromycin, etc.
How to prevent and prevent recurrence?
Tinea pedis, especially tinea pedis, is prone to recurrence or reinfection. Maintaining good lifestyle habits is essential to prevent tinea pedis, reduce its recurrence and reduce its transmission.
Personal hygiene is key
1. Keep a dry environment
A. Hands and feet should be dried between the toes (fingers) in time after bathing, shoes and socks with good penetrating air, hands and feet to avoid long-term immersion, people with tight toe seams can use clean gauze or cotton balls to sandwich in the middle or choose split-toe socks to facilitate water absorption and ventilation;
B. When palm-plantar sweating is prosperous, topical perspirant (such as 6.25%~20% aluminum chloride) or antifungal powder can be used to keep shoes and socks and feet clean and dry.
2. Pay attention to public health in baths, dormitories, etc., and do not share daily necessities such as nail clippers, shoes and socks, bathtubs, and towels with others. Sickness.
Eating a healthy diet is more important
Pay attention to avoid eating spicy and irritating foods or drinking alcohol, because itching symptoms will worsen, a healthy and balanced diet can help strengthen the body's immunity.
About the author
Liu Xiang, pharmacist in charge
PhD candidate, currently the director of the Department of Pharmacy of Shanghai Deda Hospital; He has been engaged in hospital drug dispensing, prescription review, drug preparation, drug procurement, clinical pharmacy and pharmaceutical affairs management; He is good at cardiovascular safe medication, rational use of antibacterial drugs and adverse drug reactions.
Reviewer expert: Tao Jianfei, chief pharmacist of Shanghai Yangsi Hospital
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