Athlete's foot is a common skin infection affecting the feet, caused by tinea (a fungal infection) resulting in scaling and itching.
Tinea can be easily contracted through skin-to-skin contact with an infected person or animal, or through indirect contact with an object or surface that an infected person or animal has touched. Bathroom floors, bathmats, towels, showers and communal bathing, swimming and changing room areas are common sources of infection.
On contact with your skin, the dermatophyte fungi spread to the surface layers of dead cells – they generally do not invade living skin cells. Symptoms result from the body’s allergic and inflammatory response to the infection, and they usually appear within four to 10 days.
Symptoms of athlete's foot or tinea pedis can include:
- redness and/or itching, often affecting the toe web space
- burning or stinging
- a rash that may form blisters or pustules
- raw, inflamed, cracked or scaly skin
- in more severe cases, weeping or oozing areas of skin.
Less common is ‘moccasin-type’ tinea pedis, which involves the sole of the foot and usually appears as dry, scaly patches or cracks in the skin. These may extend up onto the side of the foot in a moccasin-style pattern.
- In most cases, athlete's foot can be diagnosed by its typical appearance and history.
- When uncertain, a small scraping of skin can be taken from the affected area and sent to a laboratory for analysis.
- It may take up to four weeks for your doctor to get the results, but he or she may then be able to prescribe a more suitable treatment.
- If this fails, your doctor can refer you to a dermatologist, a doctor who specialises in skin problems.
- The usual treatment is antifungal cream applied to the affected area.
- Antifungal cream can be purchased from a pharmacy, supermarket or on prescription from your doctor.
- See your doctor if the infection becomes severe, long-lasting or if non-prescription treatments from the pharmacy have not worked, or if the skin is swollen, blistered, crusted or smells unpleasant.
- If your nails are involved you may need a prescription course of antifungal tablets rather than a pharmacy product.
Not all skin changes that look like tinea are in fact tinea, so it is important to have them checked if they do not clear up quickly. While rare, it is possible for melanoma skin cancers beneath the nail to grow unchecked, and other skin conditions can be mistaken for tinea.
People with diabetes or long term conditions that require immune-suppressing drugs (e.g. after kidney transplant) are more at risk from tinea and other infections. These people should always seek advice from their doctor for unusual looking skin changes. Older people and those with diabetes, swollen legs or suppressed immunity can also find the broken skin, caused by tinea, can become infected by other bacteria as well, causing inflammation and a more serious problem called cellulitis.
- Use an antifungal cream, lotion, gel or spray from the pharmacy or as prescribed by your doctor. Some antifungal products stop fungi growing and another type kills the fungus; others are combined with a corticosteroid drug to reduce itching.
- Keep your skin as clean and dry and possible. Shower or bathe daily, dry thoroughly between your toes and skin folds, and use a hair dryer if necessary.
- Wear socks and loose clothing made from fibres that draw moisture away from the skin, such as wool, cotton or the newer synthetic fibres.
- Wash the shower and bath using a bleach-based product every couple of days.
- Wash socks, towels and bathmats in very hot water (over 60ºC) and dry them well.
- Regularly wash floors (with very hot water and soap) where you walk in bare feet.
- Do not share towels, clothing or shoes.
Medicines for tinea can be bought from a pharmacy or be prescribed by your doctor. It is important to follow the instructions on the pack carefully. Some products need a single application only; others need regular application until one or two weeks after the infection has cleared, to prevent recurrence. If the infection has not gone away by the time you have finished the course of treatment, or it is getting worse, visit your doctor.
Once your tinea has cleared up, you should try to avoid a recurrence by:
- wearing open-toed shoes or going barefoot as often as possible
- alternating the shoes you wear each day so they can dry out – air them in the sun if possible
- drying your skin carefully after you shower or swim
- wearing jandals or plastic sandals in public bathing or changing areas to reduce the risk of picking up or passing on a fungal infection
- not sharing towels.
Tinea pedis (athletes foot) DermNet NZ, 2013
Ringworm and tinea infection - a patient's guide Family Doctor NZ, 2015