Randy Jacobs, M.D. Patient Education
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Tinea Pedis
ATHLETE'S FOOT (TINEA PEDIS): FOCUS ON FOOT CARE
Introduction
Athlete's foot is a very common skin condition--many people will develop it at least once in their lives. It is usually found between the toes, but sometimes affects the soles of the feet. The nails are usually involved. It consists of cutaneous lesions caused by Dermatophytes, a kind of skin fungi. This common condition is usually found in adolescents and young adults, particularly those who use communal changing facilities, showers, and swimming pools. It is particularly common during hot, humid weather and in those wearing occlusive footwear. It is uncommon in women and children under the age of 12. If a child displays what appears to be the symptoms of athlete's foot, chances are it's another skin condition. Athlete's foot should not be ignored--it can be easily treated, but it also can be very resistant to treatment. Athlete's foot is a term used to describe what really is a form of fungus infection of the feet. The correct term for athlete's foot is tinea pedis. The fungi that cause it are living germs, like small plants, that grow and multiply on all humans. Some people may actually have the fungus on their skin, but unless the conditions are agreeable, athlete's foot will not develop. Why some people develop athlete's foot and others don't is not clearly known. There is an immune reason for this. Athlete's foot may or may not occur among people who traditionally go barefoot. Moisture, sweating and lack of proper ventilation of the feet that present the perfect setting for the fungus of athlete's foot to grow.
Ringworm (Tinea) General Facts
Ringworm is a fungal (dermatophyte) infection of the skin, hair, or nails. It gets its name from its appearance on the skin. Ringworm often looks like a ring-shaped rash. Ringworm is caused by several different types of fungi (molds). Other names for ringworm include tinea, dermatophytosis, athlete's foot (ringworm of the feet), and jock itch (ringworm of the groin). It is not caused by a worm! You can get ringworm from people, animals, or places. People get it through contact with a person who has ringworm, or by using items such as clothes, towels, or hairbrushes that were used by someone with a ringworm infection. Animals can carry some types of fungi on their fur or skin without showing signs of ringworm infection. Sick or carrier animals can transmit fungi to people by direct or indirect (hair or dander) contact. Places like gyms, shower stalls, and floors can transmit fungus if used by someone with ringworm. Other people can catch the fungus if exposed to these places. Ringworm is easily diagnosed and treated A doctor can do some simple tests to determine whether a rash is caused by a fungus. Ringworm is usually diagnosed by simple physical examination. Ringworm can show classic physical exam findings such as the erythematous scaled annular ring of the body or groin in tinea cruris, the dry fine scale covering the soles of the feet like a "moccasin shoe" in tinea rubrum, or the interdigital maceration and scaling found between the toes in athlete's feet. Interestingly, there is a classic fungal presentation called "two foot one hand disease" in which one hand and both feet are involved with fungus. Why both hands are not involved is a medical mystery. Treatment is usually an antifungal cream applied to the sites of infection, or pills taken by mouth. If you have ringworm, you can avoid spreading it to others by: Following Dr. Jacobs' advice for proper treatment: Keep your skin, hair, and nails clean and dry. Wash towels and clothing in hot water and soap to destroy the fungus. Stay away from common areas such as community pools and gyms until your infection goes away. Ringworm can be prevented by: Keeping common-use areas clean with bleach or Ajax cleanser. Using a floor and bath cleaner that contains a fungus-killing (called "fungicidal") agent. Avoid sharing clothing, towels, hair brushes, or other personal items.
Why does athlete's foot develop?
The infection is usually caused by skin fungi called the Dermatophytes. These fungi inhabit the outer layer of skin and thrive only in nonviable tissue and therefore, generally do not invade living tissue. The fungi that cause athlete's foot like to grow in moist, damp places. Sweaty feet, not drying feet well after swimming or bathing, tight shoes and socks, and a warm climate all contribute to the development of athlete's foot. Athlete's foot is contagious along with plantar warts-- you can catch them from walking barefoot in the locker room. However, some experiments to infect healthy skin with athlete's foot have failed and often one family member may have it without infecting others living in the same house.
What does athlete's foot look like?
The infection usually begins between the toes in the toe webs, especially between the third and fourth toes, and can eventually spread to the other toe webs and later to the sole of the foot, especially the arch. Sometimes it takes on the appearance of the so-called, "Moccasin" distribution. The infected areas can be red or white in color and macerated or vesicular in appearance, often with scaling borders. The infected areas can be very pruritic or itchy. Athlete's foot may affect different people in different ways. In some, the skin between the toes (especially the last two toes) peels, cracks and scales. In others, there is redness, scaling and even blisters on the soles and along the sides of the feet. These skin changes may be accompanied by itching. Toenail infections can also occur and can be very stubborn to treat. Toenail infections result in scaling, crumbling and thickening of the nails and even nail loss. Not all rashes on the feet are athlete's foot. Before treating a foot rash yourself, check with Dr. Jacobs, who can diagnose the condition and prescribe the correct medication. Using over-the-counter preparations on a rash that is not athlete's foot may make your condition worse. If athlete's foot isn't treated, it can result in skin blisters and cracks that can lead to bacterial infections.
How is athlete's foot treated?
Once the fungus is diagnosed, treatment should begin immediately. For simple cases, anti-fungal creams may be prescribed. The creams can relieve the symptoms fairly quickly. In more severe cases, Dr. Jacobs may suggest foot soaks before applying antifungal creams. Ask your pharmacist for Domeboro soaks. Soak your feet for 15 minutes prior to applying the creams. If your athlete's foot is stubborn, antifungal pills may be prescribed. Please read about their side effects. Toenail infections are very difficult to treat. Research is ongoing to try to find effective ways to treat toenail fungal infections. It's important to continue the use of your prescribed antifungal creams and to take all medication. The creams should be used for three months after the fungal infection is visibly gone. While your skin may look better, the infection can remain for some time afterwards and could recur. A Word About Oral Medications: If your tinea is severe, Dr. Jacobs may discuss with you the possibility of using oral medications to treat your infection. There are three main oral medications used in the treatment of tinea: Griseofulvin, Nizoral Tablets, Lamisil Tablets, and Sporanox Capsules. As with any medical decision, one must always weigh risks and benefits when deciding on choosing a particular form of therapy. The oral medications do have possible side effects that you should be informed of. You should not use alcohol with these medications. You should inform Dr. Jacobs if you have any history of alcohol intake, liver disease, hepatitis, or any chronic diseases. All oral antifungal medications are listed as able to cause side effects involving allergies, death, changes in blood count, kidneys, and skin. Please read the package inserts for details. Your pharmacist can also give you an informational sheet for each drug in question. Of note, Nizoral is known to cause liver toxicity and inflammation in 1 in 10,000 patients. This has been fatal in certain patients, even after taking the medication for a short time. Lamisil Tablets, and Sporanox Capsules can cause the same, but the incidence is much less, and these are considered safer medications for long term use. To a lesser degree, Griseofulvin is also known to cause liver toxicity and inflammation. Griseofulvin does have a cross reactivity in patients who are allergic to penicillin. If the benefits outweigh the risks in your condition, you may want to take an oral medication for your infection. Dr. Jacobs may order blood tests, initially, or after two weeks, and then periodically for Nizoral Tablets, Lamisil Tablets, and Sporanox Capsules. Dr. Jacobs may order blood tests, initially, and then at monthly or six week intervals for patients requiring Griseofulvin for longer than 3 weeks. If you have any further questions, please ask Dr. Jacobs at your next appointment. He will be happy to help you.
What is the best way to prevent athlete's foot?
You can prevent athlete's foot by following some simple rules:
- Wash your feet daily, especially in between toes.
- Dry your feet thoroughly, especially in between your toes.
- Avoid tight footwear, especially in the summer. Sandals with white cotton socks are best.
- Wear cotton socks and change them twice a day or more frequently if they become damp.
- Don't wear socks made of synthetic materials.
- Dust an anti-fungal powder into your shoes in the summertime.
¼ Use rubber type sandals whenever showering or walking in a public locker room or shower. Note, if you must expose your feet as in certain sports like Tae Kwon Do or Karate, be sure cleanse fee after each workout.